Summit Heated Seat 2 The Heated Seat 2.0 is rechargeable (included lithium batteries) and provides up to four hours of continuous warmth per charge, plus doubles as charging port for mobile devices. Other features include a waterproof, nylon protective shell, no-slip bottom, removeable battery and heat source for cleaning and an ergonomic shape that fits most treestands. Features: Provides 4 hours of bun-warming. continuous warmth per charge Rechargeable lithium battery with dual USB ports Doubles as charging port for mobile devices Waterproof nylon protective shell Ergonomic shape fits most treestands