ThermaCELL ProFLEX Heated Insoles. ThermaCELL Heated Insoles ProFLEX are a serious heating product for people who need it most. These cutting edge remote-controlled insoles warm your feet to the perfect temperatures (100F/111F) so they don't overheat, then sweat and freeze. There is also a No Heat setting so the heat can be temporarily turned off and on as needed. Different than other heating products on the market, ThermaCELL Heated Insoles ProFLEX have a removable cushioned rechargeable battery so you can swap out batteries to extend duration of heating during the day without removing insoles from footwear. This allows for quick and easy replacement of batteries, rather than having to carry and change insoles throughout the day. The batteries charge through USB or a wall charger, so you can charge virtually anywhere. These insoles are also made out of breathable polyurethane foam that conducts heat efficiently, offers great shape retention and shock absorbency for all-day comfort. Includes: Includes 2 Rechargeable Lithium-Ion Polymer batteries, 1 Remote Control (battery included), 1 Wall Charger with USB Cable, 1 Drawstring Bag, 1 Instruction Booklet Rechargeable, removable battery Adjustable Temperature Materials: Polyurethane foam, Lithium-Ion Polymer Battery