Sanyo KIR-SL2SS Kairo Hand Warmer with Eneloop Batteries and Charger, Silver Operates on 2 AA Eneloop precharged rechargeable batteries (included) 3 Temperature Settings (95/104/109 degrees) Continuous Usage Times: 1-3 Hours on LOW / 1-1.25 Hours on HIGH / 1-2 Hours on TURBO Power level indicator ensures efficient charging Eneloop batteries can be charged up to 1000 times