The Gerbing Rechargeable 3V Heated Insoles are the answer to eliminating cold toes for up to 8 hours on a single charge. The integrated heating system under the toes teams up with rechargeable 3 Volt batteries that are embedded in the heel. You no longer have to worry about misplacing or fumbling with installing the batteries; just charge up the insoles, turn them on, and immediately feel the warmth! Handy trim lines on the Gerbing Insoles guide you to customize the fit to your footwear, and the thin profile of the insole guarantees a comfortable fit.