What the manufacture says:
ThermaCELL® Heated Insoles
- Remote-controlled, foot-warming insoles
- Medium, High and No Heat settings
- Regulates heat output by body heat and outdoor temperatures
Slip these wireless, rechargeable and remote-controlled, heated insoles into any pair of boots or shoes and enjoy instant, adjustable warmth with just the push of a button. Great for hunting, hiking, ice fishing or just to add some soothing warmth to your favorite slippers. Your feet will never overheat, because the insoles warm up to a predetermined temperature based on your remote-control setting. Compact and durable, the remote control has a 7-ft. range and three settings: Medium (100°F); High (110°F); and the No Heat option conserves battery life. Once the heated insoles reach the maximum temperature, they temporarily turn themselves off. They turn themselves back on when the temperature drops – just like a household thermostat. The soft, durable, customizable and water-resistant insoles contain the remote receivers that deliver the heat-adjustment signals to the full-length heat sensors. These advanced heat sensors maximize your comfort by regulating the output according to your body heat and outdoor temperatures. Internal lithium-ion batteries are rechargeable up to 500 uses. On Medium, charges last for up to five hours. Tested by SATRA for durability, heating and safety. Includes charger and a remote-control battery.
Sizes: S(3.5 to 5) M(5.5 to 7), L(7.5 to 9), XL(9.5 to 11), 2XL(11.5-13).
Flexible: Yes, except for the heel where the battery is.
Batteries are not replaceable.
Batteries will charge up to 500 times. (Manufacture Statement)
Recharge time: 4 hrs.
Batteries are 3.7 volts.