USB rechargeable heated insole: The heated insole features innovative heating technology, crafted from comfortable and flexible EVA elastic material, offering excellent cushioning, light and portable. The heater connects via a USB interface, providing a large heating surface for even heat distribution, with temperatures reaching up to 42 C/108 F. Cleanable and rechargeable use: This USB insole is made from waterproof, washable, and reusable material. It can be cleaned with a brush but is not machine washable. Please ensure it is completely dry before using it after washing. Versatile, Best Gift Heated Insole Keeps Feet Warm In Cold Winter, with temperatures up to 42 C/108 F. Whatever your activity��skiing, outdoor sports, camping, housework, hunting, hiking, fishing, etc.��you can stay warm. It makes an excellent Christmas gift. All products from us undergo strict quality checks. If there is any quality issue or you are not satisfied with the product, please contact us. We will provide you with the best solution.