High-quality Materials: This heated insoles adopt new heating technology, made oft and comfortable EVA stretch material, with good cushioning, portable Light. It can provide the warmth of everyday life and is ideal to keep your body warm when the temperatures get cold. USB Heated Insoles: The heatable insoles is convenient with a USB interface. Can be put right in the shoes, easy to use, just put on your shoes and enjoy the warmth. Cleanable & Repeatable Use : This usb insoles material has a waterproof effect, is washable and reuseable, you can wash it via brush, not for machine washing, it should be noted that it needs to be dried after washing, and must be completely dried before use. Free Size Adjustment : Electric heated foot warmer insole can be tailored to your size. According to the easy cutting route you can cut the soles for your own shoes. Suitable for most shoes. Wide Range of Uses: The heated shoe insoles keep your feet warm in cold winter, the temperature will reach up to 40-50 C(depends on environmental temperature changes), so no matter where you go, you can keep you warm suitable for chores,fishing etc, is best christmas gift.