Best Pulsar Generators for Air Conditioners: 2026 Buying Guide

The SoftStart Home is a soft starter device designed to reduce AC and heat pump compressor startup power consumption by up to 70%. It's specifically engineered for off-grid living, RV owners, solar power users, and anyone relying on generators or low-amperage power systems. The device addresses a critical problem: most AC units draw enormous inrush current at startup, often exceeding what smaller generators can supply.

The standout feature is its ability to dramatically reduce startup power demands while maintaining normal running efficiency. Real-world users report successfully running 5-ton heat pumps on 11,500-watt generators that previously couldn't handle the load. Beyond compatibility, the soft start technology extends compressor lifespan by minimizing thermal stress during startup cycles. Installation is genuinely quick, taking approximately 15 minutes with the included crimp connectors, zip ties, and adhesive backing. The QR code linking to brand-specific installation guides makes setup accessible even for non-technical users.

Build quality appears solid with a compact 2.75-pound design that fits tight spaces. The device operates on 110-240V and supports systems up to 6 tons (72,000 BTUs), covering most residential and light commercial applications. Customer support stands out as a genuine differentiator, with users praising direct access to technical staff and willingness to troubleshoot via video chat.

The primary limitation is installation precision. One user initially experienced mid-operation shutdowns due to misplaced wires, though support quickly resolved the issue. The $369 price tag is substantial for homeowners without generator constraints, though it becomes cost-effective for RV owners or solar users facing AC startup challenges. Warranty and long-term reliability data beyond the user reviews aren't detailed in available materials.

Overall, the SoftStart Home delivers genuine value for its target audience. If you operate an AC or heat pump on a generator, solar system, or other limited-power setup, this device solves a real problem while extending equipment life. For standard grid-powered homes, the benefit is primarily quieter startup and minor efficiency gains, which may not justify the investment.

Model: SoftStart Home (Part Number JP-M11G-RG34)

Brand: SoftStartRV By NetworkRV

Voltage: 110-240V compatible

Capacity: Up to 6 tons (72,000 BTUs)

Power Reduction: Up to 70% inrush current reduction

Weight: 2.75 pounds

Package Dimensions: 9.72 x 5.39 x 4.29 inches

Installation Time: Approximately 15 minutes

Compatibility: Works with all major HVAC brands, AC units, and heat pumps

Included Accessories: Crimp-on connectors, zip ties, adhesive backing, step-by-step instructions, QR code for brand-specific guides

Who Should Buy This Product: RV owners with AC systems, off-grid homeowners using solar power, anyone operating AC units on generators or backup power systems, and users experiencing startup surges that cause flickering lights or equipment strain.

Who Might Skip It: Standard grid-powered homes without generator constraints, commercial applications exceeding 6 tons, and budget-conscious buyers prioritizing lowest upfront cost over equipment longevity.

Key Considerations: Verify your AC unit's tonnage is at or below 6 tons before purchasing. Download and print the brand-specific installation PDF before starting setup to avoid wire placement errors. Contact customer support via the included direct number if you're uncertain about any installation step. This device is most cost-effective for users facing AC startup power limitations rather than those seeking minor efficiency gains.

Installation Prerequisites: Basic electrical knowledge helpful but not required, as comprehensive guides and video support are available. Ensure your generator or power system can handle normal running wattage (not just startup). The device solves startup power issues but doesn't reduce ongoing energy consumption.

The Pulsar PG2300iS is a portable inverter generator designed for campers, tailgaters, homeowners, and anyone needing reliable backup power without excessive noise. At 2300 peak watts and 1800 running watts, it delivers genuine utility for RVs, small appliances, power tools, and sensitive electronics. The 59dB noise level makes it one of the quieter gas generators available, earning praise from users who were surprised by how quietly it operates.

The standout feature is its inverter technology, which produces a stable sine wave output safe for powering laptops, smartphones, and other sensitive devices. Multiple users confirm it starts easily on the first or second pull, runs smoothly, and maintains consistent power delivery. The dual 120V outlets, 12V DC cigarette outlet, and USB port provide flexibility for various devices and charging needs. The included economy mode intelligently reduces fuel consumption during lighter loads, extending runtime to approximately 6 hours at half capacity.

Build quality feels solid with a steel frame and compact dimensions of 19.7 inches by 11.22 inches by 17.91 inches. At 48 pounds, it remains genuinely portable for one person to handle, though not featherweight. The included accessories such as engine oil, spark plug wrench, oil funnel, and 12-volt charging cables mean you can start using it immediately without additional purchases.

One limitation worth noting is that the 1800 running watts may struggle with larger air conditioning units or high-demand appliances without parallel capability. The small 1.18-gallon tank requires refueling more frequently during extended use. Some users report the stated wattage can be optimistic in real-world scenarios, particularly when powering multiple devices simultaneously.

Overall, the Pulsar PG2300iS delivers excellent value for recreational use, emergency backup, and light commercial applications. Its quiet operation, clean power output, and portable design make it a smart choice for anyone prioritizing low noise and device protection over maximum wattage. The parallel capability adds future flexibility if power needs increase.

Power Output: 2300 watts peak, 1800 watts running

Engine: 80cc 4-stroke, recoil start with low oil shut-off and automatic voltage regulator

Fuel: Gasoline, 1.18-gallon tank capacity

Runtime: Up to 6 hours at half load with economy mode

Outlets: Two 120V 13A household outlets, one 12V 8A cigarette outlet, one 5V USB port

Noise Level: 59 decibels

Output Quality: Stable sine wave with 5% or less total harmonic distortion

Dimensions: 19.7 inches L x 11.22 inches W x 17.91 inches H

Weight: 48 pounds

Frequency: 60 Hz

Warranty: 1 year manufacturer warranty

Compliance: CARB compliant for California emissions standards

Best For: The PG2300iS suits camping trips, RV travel, tailgating events, emergency home backup power, and jobsite use where noise restrictions exist. It works well for powering laptops, phones, small appliances, and power tools that don't exceed 1800 running watts.

Power Considerations: With 1800 running watts, you can reliably power most small window AC units, refrigerators, microwaves, and multiple devices simultaneously. For larger air conditioners or high-demand tools, consider the parallel capability by purchasing a second unit.

Noise Comparison: At 59dB, this generator is quieter than most gas-powered mowers and push equipment but louder than conversation distance. It produces pleasant background noise rather than harsh engine sound, making extended operation more tolerable.

Fuel Efficiency: The economy mode feature significantly extends runtime by reducing engine speed during lighter loads. This feature is crucial for camping where refueling frequently may be inconvenient.

Maintenance: Regular fuel system maintenance and seasonal storage procedures are recommended. The included manual and accessories support straightforward upkeep for long-term reliability.

The Pulsar PGD40ISCO is a portable inverter generator designed for users who need reliable backup power without sacrificing portability. At just 46 pounds, it's engineered for RV camping, tailgating, emergency home backup, and light commercial work. The inverter technology ensures clean power output, making it safe for sensitive electronics like computers, medical devices, and modern appliances.

Performance-wise, this generator delivers 4000 peak watts and 3200 rated watts of continuous power. Real-world testing from owners confirms it reliably powers 13,500 BTU air conditioning units, microwave ovens, and multiple household appliances simultaneously. The 145cc 4-stroke engine starts reliably even in demanding conditions, with users reporting consistent first-pull starts. At half load, the 1-gallon fuel tank provides approximately 4 hours of runtime, and the low-idle control feature maximizes efficiency during lighter load periods.

Build quality reflects solid engineering with aluminum, plastic, and steel construction designed to withstand outdoor use. The generator includes two 120V household outlets and one 120V 30A RV outlet, providing versatility for different power needs. Included accessories like engine oil, spark plug wrench, and oil funnel mean you can start using it immediately without additional purchases.

The main considerations are noise levels and fuel capacity. At 59dB, it's noticeably louder than premium competitors but quieter than traditional open-frame generators. The 1-gallon tank requires refilling every 4-6 hours under heavy AC load, and some users report fuel cap ventilation issues in extreme heat. These are minor trade-offs for the exceptional portability and value proposition.

Overall, the Pulsar PGD40ISCO represents excellent value for budget-conscious buyers needing a portable, quiet-enough generator for camping, RVs, and emergency backup. Its lightweight design, clean inverter power, and proven reliability make it a smart choice for anyone prioritizing portability and ease of use over premium quiet operation.

Power Output: 4000 watts peak, 3200 watts rated continuous

Engine: 145cc 4-stroke, 5.5 HP, magneto ignition system

Fuel: Gasoline, 1-gallon tank capacity, 4-hour runtime at half load

Voltage: 120V AC, 60 Hz frequency

Outlets: Two 120V 20A household outlets, one 120V 30A RV outlet (TT-30R)

Noise Level: 59 dB at quarter load

Weight: 46 pounds (47.3 lbs with packaging)

Dimensions: 18.9 inches L x 11.4 inches W x 17.3 inches H

Safety Features: CO Sentry carbon monoxide detection, automatic voltage regulation

Warranty: 3-year limited warranty

Best For: This generator is ideal for RV owners, campers, tailgaters, and homeowners seeking portable emergency backup power. The clean inverter output makes it perfect for protecting sensitive electronics and modern appliances. Its lightweight design suits users who need to transport and manually position the unit frequently.

Power Requirements: With 3200 watts of continuous power, it handles most household appliances, power tools, and AC units up to 13,500 BTU. Calculate your typical load before purchase: laptops and phones use minimal power, while air conditioners and heaters demand significant wattage.

Fuel Considerations: The 1-gallon tank provides adequate runtime for casual use and moderate loads. Plan for frequent refueling during extended operation or heavy AC usage. Keep extra fuel stored safely in approved containers for longer trips.

Noise Sensitivity: At 59dB, this generator produces noticeable sound during operation. If operating in noise-sensitive environments, place it at a distance and use acoustic barriers. For ultra-quiet operation, consider premium inverter models, though they cost significantly more.

Maintenance: The included oil and tools make initial setup simple. Regular maintenance includes checking oil levels, replacing spark plugs annually, and running the unit monthly to keep the engine conditioned. Proper maintenance ensures years of reliable service.

The Pulsar PG2200BiS is a 2,200-watt portable dual fuel inverter generator designed for camping enthusiasts, homeowners needing backup power, and outdoor event organizers. Its compact size and parallel capability make it versatile enough for weekend trips or as part of a larger power solution. The CARB and EPA compliance ensures it meets strict environmental standards.

What truly sets this generator apart is its whisper-quiet 60dB operation combined with stable sine wave inverter technology. This means you can safely power sensitive electronics like laptops and medical equipment without worry, while neighbors won't hear it running. The dual fuel flexibility lets you choose between gasoline for longer runtimes (8 hours per tank) or LPG for cleaner, potentially cheaper operation depending on your location and fuel availability.

Build quality is solid for the price point, featuring a 3HP single-cylinder 4-stroke engine with air cooling and an 80cc displacement. The compact carrying case design makes transport straightforward, and the included accessories (propane hose, oil bottle, spark plug wrench, funnel) show attention to practical user needs. Low oil indicator with automatic shutdown protection extends engine life by preventing damage from dry running.

The main limitation is runtime on LPG mode, which drops to just 75 minutes on a 1-pound tank, making it less practical for extended propane-only use. Additionally, the 1,600 rated watts in LPG mode is noticeably lower than the 1,800 watts on gasoline, restricting which appliances you can run simultaneously. These tradeoffs are typical for dual fuel generators but worth considering based on your primary fuel preference.

Overall, the Pulsar PG2200BiS delivers excellent value for users prioritizing quiet operation and fuel flexibility. If you need a generator for camping, backup power, or events where noise matters, this model excels. The parallel capability adds future-proofing, though the LPG runtime limitations mean gasoline mode will likely be your primary option for extended use.

Power Output: 2,200 peak watts / 1,800 rated watts (gas) and 2,000 peak watts / 1,600 rated watts (LPG)

Engine: 80cc, 3HP single-cylinder, 4-stroke, OHV, air-cooled

Outlets: Two 120V 15A AC outlets, one 5V integrated USB outlet, parallel sockets

Fuel Tank Capacity: 1.18 gallons (gasoline mode)

Runtime: 8 hours at 1/2 load (gasoline) and 75 minutes at 1/2 load (1-pound LPG tank)

Noise Level: 60dB

Weight: 44 pounds

Voltage: 120 volts

Technology: Inverter with stable sine wave, parallel capability

Compliance: CSA, EPA, CARB compliant

Warranty: 1-year limited

Included Accessories: Propane hose, spark plug wrench, 10W30 oil bottle (350ML), funnel

Best For: This generator is ideal for camping trips, RV owners, tailgating, outdoor events, and homeowners seeking quiet backup power. The dual fuel capability appeals to users in areas where propane is readily available or more affordable than gasoline.

Power Needs Assessment: With 1,800 watts available, you can run most household essentials including refrigerators, power tools, and multiple small devices simultaneously. However, you cannot run large appliances like air conditioners or electric heaters. The USB outlet is convenient for charging phones and tablets without occupying an AC outlet.

Fuel Considerations: Choose gasoline mode for extended runtime needs (8 hours per tank) and propane mode for cleaner operation or when storing the unit long-term. Propane fuel stores indefinitely without degrading, making it better for seasonal or emergency backup use. The 75-minute LPG runtime means you'll need backup propane tanks for all-day operation.

Parallel Capability: If you anticipate needing more power in the future, you can purchase a second PG2200BiS and connect them in parallel to double your output to 3,600 watts. This makes the generator a scalable solution that grows with your needs.

Maintenance: Regular oil changes and fuel stabilizer use will keep this generator running reliably for years. The included oil bottle and low oil shutdown protection make maintenance straightforward even for beginners.

The Pulsar GX420N is a 4,200-watt portable inverter generator designed for camping enthusiasts, RV owners, and homeowners needing reliable emergency backup power. Its ultra-lightweight 49.5-lb suitcase design makes it genuinely portable for solo transport, unlike bulkier competitors that require two people or a dolly.

The standout feature is the combination of quiet operation and exceptional fuel efficiency. At just 65dB from 10 feet away, it runs nearly silent compared to traditional generators, while delivering an impressive 6-hour runtime at half load on a single gallon of fuel. The pure sine wave technology ensures safe, stable power for charging laptops, smartphones, and other sensitive electronics without risk of damage.

Build quality feels solid despite the lightweight construction. The compact suitcase design houses a reliable gasoline engine with recoil start ignition, and Pulsar backs it with a 3-year manufacturer warranty. The three output options (dual 120V outlets, 12V cigarette outlet, and USB charging port) cover most real-world needs for camping and emergency scenarios.

The main limitation is the small 1.06-gallon fuel tank, which means you'll need to keep spare gas cans nearby for extended use. Some users report minor smoking during the initial break-in period, though this typically subsides after a few hours of operation. Parallel capability allows connecting two units for doubled power output if you need more capacity.

Overall, the Pulsar GX420N delivers excellent value for portable power. It excels at powering RV appliances, camping equipment, and emergency home backup while remaining genuinely portable and quiet enough for campgrounds and residential areas.

Power Output: 4,200 peak watts, 3,200 running watts

Fuel & Runtime: Gasoline engine, 1.06-gallon tank capacity, up to 6 hours at half load

Noise Level: 65dB at 10 feet (very quiet operation)

Portability: 49.6 lbs, compact suitcase design measuring 20.47 x 11.81 x 17.52 inches

Output Options: Dual 120V outlets, 12V cigarette outlet, USB direct charging port

Technology: Pure sine wave inverter technology, parallel capability, 60Hz frequency

Warranty: 3-year manufacturer coverage

Included Accessories: 10W30 engine oil, oil funnel, spark plug wrench, screwdriver, user manual

Best For: This generator is ideal for RV camping, tailgating, outdoor events, emergency home backup, and anyone needing portable power in a lightweight package. The quiet operation makes it perfect for campgrounds with noise restrictions.

Consider If: You need reliable power for sensitive electronics like laptops and phones, value fuel efficiency and long runtime, or want a generator light enough to move solo. The parallel capability appeals to users who might need to upgrade to higher wattage later.

Skip If: You need continuous power for 8+ hours without refueling, require more than 3,200 running watts, or prefer a quieter electric generator. The small fuel tank means frequent refueling for all-day use.

Pro Tips: Keep spare gasoline containers nearby for extended camping trips. Let the unit run through its break-in period to minimize smoking. Position the generator downwind and away from windows to reduce noise impact on others.

The Pulsar PG1202SA is a compact, gas-powered portable generator designed for homeowners, campers, and outdoor enthusiasts who need reliable backup power without the expense of larger models. With 1200 peak watts and 900 running watts, it effectively powers small appliances, tools, and camping equipment during emergencies or off-grid adventures. This 35-pound unit is easy to transport and store, making it a practical choice for those with limited space.

Performance and reliability are this generator's standout qualities. The recoil-start engine fires up easily and runs smoothly, delivering consistent power for multiple devices thanks to its dual 120V AC and 12V DC outlets. Users consistently praise its fuel efficiency and ability to run for up to 5 hours on a single 1.1-gallon tank. Even after extended storage, the engine restarts reliably with minimal effort, a testament to solid engineering in this price range.

Build quality reflects a practical balance between durability and affordability. The generator uses steel, aluminum, and cast iron construction with a carrying handle for portability. While most users report years of dependable service, some have noted that vibration can cause minor leaks at fuel tank seams and gasket connections over time, requiring periodic maintenance and careful fuel handling.

The main limitation is noise level and power capacity. This generator operates at moderate to high decibel levels, which is typical for small gas units but worth noting for noise-sensitive environments. Additionally, it is not designed for heavy-duty applications like air conditioners or large power tools, so users must match their power needs carefully to the 900-watt running capacity.

Overall, the Pulsar PG1202SA is an excellent budget-friendly option for emergency backup power, camping trips, and outdoor work. It delivers reliable performance where it matters most, backed by proven longevity and user satisfaction. Recommended for anyone seeking dependable portable power without premium pricing, provided they understand its limitations for high-power applications.

Power Output: 1200 peak watts, 900 running watts at 60 Hz frequency

Engine: 71cc 2-stroke gas engine with recoil start ignition, 40:1 fuel mix ratio

Fuel Tank: 1.1 gallons capacity with approximately 5-hour runtime

Outlets: 120V AC (7.5A rated) and 12V DC battery charging outlet

Dimensions & Weight: 16 inches length, 15.4 inches width, 17.1 inches height, 35 pounds total

Warranty: 1-year limited manufacturer warranty from Pulsar Products Inc.

Emergency Backup Power: Powers essential devices during home power outages, including lights, phone chargers, small appliances, and medical equipment.

Camping & Outdoor Recreation: Provides reliable power for RVs, campers, and outdoor events without access to grid electricity.

Jobsite Tools: Runs power tools and equipment for construction, landscaping, and maintenance work in remote locations.

Tailgating & Events: Supplies power for coolers, entertainment devices, and lighting at outdoor gatherings.

NOT Recommended For: Air conditioning units, large refrigerators, power-hungry tools, or any application requiring sustained power above 900 watts.

The Pulsar GD10KBN is a dual fuel inverter generator designed for homeowners and outdoor enthusiasts who need reliable backup power without breaking the bank. With 10,500 peak watts and 8,000 running watts, this generator handles most household essentials including lights, appliances, and central air conditioning systems during power outages or emergencies.

What sets this model apart is its dual fuel capability and impressive runtime. You can switch between gasoline and propane to match your fuel availability and budget, while the 8-gallon tank delivers up to 10 hours of operation at half load. The RV-ready 15-50R outlet makes it equally suitable for campgrounds and tailgates, while the digital multimeter keeps you informed about voltage, frequency, and maintenance schedules in real time.

Build quality and portability are solid for the price range. The 125-pound frame includes a wheel kit for easier transport, rubber outlet covers protect connections from dust and debris, and comprehensive safety features like automatic voltage regulation, overload protection, and low oil shutdown prevent damage to your electronics and the unit itself.

The primary drawback is noise output. While rated at 68 dB, real-world performance shows this generator operates louder than that specification under full load, with users comparing it to a loud conversation or yelling match. This may concern neighbors in close proximity, though it remains quieter than traditional open-frame generators.

The Pulsar GD10KBN represents smart value for buyers prioritizing fuel flexibility, runtime, and versatility over absolute quiet operation. It's an excellent primary or backup generator for residential use and outdoor adventures, backed by a solid 3-year warranty.

Power Output: 10,500 watts peak, 8,000 watts running, 10.5 kW maximum engine power

Fuel System: Dual fuel (gasoline or propane), 8-gallon tank capacity, up to 10 hours runtime at half load

Engine: 312cc 4-stroke engine with electronic ignition system and 60 Hz frequency

Voltage: 120/240 volts with automatic voltage regulation

Outlets: 6 total power outlets including RV-ready 15-50R connector

Dimensions and Weight: 29.9 inches length, 21.5 inches width, 22.8 inches height, 125 pounds total weight

Noise Level: 68 dB rated, includes wheel kit for portability

Safety Features: Overload protection, short circuit protection, low oil automatic shutdown, digital multimeter display with hour meter and maintenance alerts

Warranty: 3-year manufacturer coverage

Who Should Buy This Generator? The Pulsar GD10KBN suits homeowners seeking affordable backup power for outages, RV enthusiasts who need mobile electricity, and anyone wanting fuel flexibility without premium pricing. It's ideal for those prioritizing runtime and versatility over absolute quiet operation.

Power Requirements: With 8,000 running watts, this generator powers most household circuits simultaneously. A central A/C unit typically draws 3,500-5,000 watts, leaving capacity for refrigerators, lights, and other appliances. Calculate your peak load before purchase to ensure adequate capacity.

Fuel Considerations: Dual fuel capability offers significant advantages. Propane stores longer without degradation, making it better for emergency preparedness. Gasoline provides better availability at gas stations. Consider your local fuel access and storage preferences when choosing your primary fuel source.

Noise Management: At 68 dB rated (higher under load), this generator suits residential backup but may disturb neighbors during extended use. Place it away from windows and doors, or consider a generator enclosure if noise is a concern. It's quieter than traditional generators but louder than premium inverter models.

Maintenance and Setup: Follow the instruction manual for proper startup procedures. The digital display helps track maintenance intervals. Connect directly to your circuit breaker panel with proper installation for seamless home backup, rather than using extension cords for multiple devices.

The Pulsar 7250W dual fuel inverter generator is a versatile power solution designed for homeowners, RV enthusiasts, contractors, and anyone needing reliable backup electricity. Its dual fuel capability sets it apart from single-fuel competitors, offering both gasoline and propane options to match your fuel availability and runtime preferences.

The standout features include remote start convenience with an included battery, eliminating frustration with manual recoil pulling in emergencies. The 240-volt output capability is a significant advantage, allowing you to power larger appliances and professional tools beyond what standard portable generators offer. Built-in inverter technology protects sensitive electronics like computers and medical devices, making it safer than conventional generators for modern equipment.

Build quality appears solid with a 312cc OHV 4-cycle engine, enclosed frame design, and comprehensive safety features including CO detection and automatic low-oil shutdown. The digital control center provides useful real-time information about voltage, load, and operating hours. Multiple outlet types, including USB ports, RV hookup, and professional-grade connectors, demonstrate thoughtful design for diverse applications.

The main drawbacks center on its 118-pound weight, which requires physical effort or equipment to move, and the added complexity of maintaining dual fuel compatibility. The 3.8-star rating suggests some users experienced reliability or noise-level concerns worth investigating through detailed reviews before committing to this investment.

Overall, the Pulsar 7250W represents a capable mid-range generator for users who value fuel flexibility, electronics protection, and 240-volt capability. It suits residential backup power, recreational use, and light commercial applications where dual fuel convenience justifies the added complexity and weight.

Power Output: 7,250 peak watts / 6,000 running watts (gasoline), 6,500 peak watts / 5,500 running watts (propane)

Voltage: 120V and 240V output

Engine: 312cc OHV 4-cycle

Weight: 118 pounds

Outlets: 1x USB-A, 1x USB-C, 2x GFCI 120V 5-20R, 1x 120V/240V L14-30R, 1x 120V TT-30 RV

Starting Options: Remote start, electric start, and recoil start

Key Features: Automatic voltage regulation, CO sensor, overload protection, parallel capability, digital control center

Included: Battery pack, engine oil, funnel, spark plug wrench, propane hose

Best For: This generator suits homeowners seeking reliable backup power, RV owners who need flexible fuel options, and contractors requiring both 120V and 240V output on job sites.

Consider This If: You prioritize electronics protection, want the flexibility of dual fuel operation, need 240-volt capability, and don't mind the 118-pound weight for stationary or semi-portable use.

Skip This If: You need a lightweight portable generator for frequent transport, prefer single-fuel simplicity to minimize maintenance, or operate on extremely tight budgets where basic single-fuel models suffice.

Maintenance Tips: Familiarize yourself with both fuel systems before operation. Keep propane hose and connections clean. Perform regular oil checks and follow the manual's maintenance schedule to maximize reliability and lifespan.