The Mobile Warming 7.4-volt Heated Glove Liners are designed to fit under any glove. Engineered with high-quality stretch polyester, the Mobile Warming Heated Glove Liners are ultra-thin, but provide long-lasting warmth. A set of ultra-slim, 7.4-volt rechargeable Lithium-Ion batteries provide exquisite heating power. The integrated light-weight batteries give you maximum comfort and long-lasting power. Adjust temperature easily with an integrated touch button controller in-cuff. Choose from four different temperature ranges to ensure you can find your perfect temperature.