The generator experts present the #1 selling automatic standby generator for 24/7 automatic power protection. Choose what you would like to backup, so you can keep your life going without disruption. Unlike a portable generator that requires frequent refueling, the automatic standby generator runs on existing natural gas or LP fuel. The Generac OHVI engine is designed for extended run times - up to 3,000 hours of service with proper maintenance and typical usage. Exclusive Quiet-Test feature means you can be confident that the generator is ready to automatically power up when the power goes out. UL Listed. THIS ITEM CANNOT BE RETURNED.