The Heated Insoles Foot Warmer from ThermaCELL® offers remote operation and has no wires or external batteries. The foot warmer is designed to keep feet warm, but not hot, so feet do not sweat and freeze. The rechargeable foot warmer is operated by a wireless remote control, while the foot warmer is worn inside users’ shoes or boots. The foot warmer is powered by rechargeable, built-in lithium-ion polymer batteries.
You can find more information on the Schawbel Technologies, LLC website.