Coleman OneSource powers your outdoor gear and devices with one interchangeable rechargeable battery system Seat cushion has 4 adjustable heat settings; one fully charged 4800 mAh lithium-ion battery keeps the heat going for 1.5 hours on high (133°F), 2 hours on medium (123°F), 3 hours on low (113°F), or 2.5 hours on pulse setting (low to high) Dual port battery dock on the side holds up to 2 rechargeable lithium-ion batteries (2nd battery sold separately), doubling the runtime; also charges your phone or other devices Seat folds in half for easy storage; back metal support bar can double as a carry handle to the bleachers or sidelines Steel frame plus weather-resistant fabric and nontoxic PU coating help protect against water and rain Bleacher hook wraps around the base of bleacher adding stability to the seat while cheering on your team 1-Year Limited Warranty (Seat); 3-Year Limited Warranty (Battery).