1. USB Charging Heated Insoles: This heated insole adopts a brand - new heating technology and is made of comfortable EVA elastic material. It has good cushioning performance, is easy to carry and light in weight. The heater is heated by connecting a USB cable through a comfortable USB interface. It has a large heating area, uniform heat distribution, and the temperature can reach 42 degrees Celsius/108 degrees Fahrenheit. 2. Cleanable and Rechargeable: The material of this USB insole is waterproof, washable and reusable. You can clean it with a brush, but do not machine - wash it. Note that after cleaning, it should be air - dried, and it must be completely dry before use. 3. Versatile and an Excellent Gift: The heated insole can keep your feet warm in the cold winter, and the temperature can reach 42 degrees Celsius/108 degrees Fahrenheit. Therefore, you can stay warm wherever you go. It is very suitable for activities such as skiing, outdoor sports, camping, doing housework, hunting, hiking, fishing, etc. It is an excellent Christmas gift. 4. All our products have passed strict quality inspections. 5. If there are any quality problems with the product or you are not satisfied with the product, please contact us. 6. We will provide you with the best solution.