SB rechargeable heated insole: The heated insole adopts new heating technology, made of comfortable and comfortable EVA elastic material, with good cushioning, portable and lightweight, the heater is comfortable USB interface is heated by USB cable, the heating surface is large, the heat is evenly distributed, the temperature Up to 42 C/108. Cleanable and rechargeable use: This USB insole material is waterproof, washable and reusable, you can wash it with a brush, not machine washable, it should be noted that it needs to be dried after washing, it must be completely dry before use . Versatile, Best Gift Heated Insole Keeps Feet Warm In Cold Winter, Temperatures Up To 42 C/108, So Wherever You Go, You Can Stay Warm, Perfect For Skiing & Outdoors, Other Sports, Camping, Housework, Hunting , hiking, fishing, etc., is the best Christmas gift. all Products From Us Have Undergone Strict Quality Checks. if There Is Any Quality Problem Or You Are Not Satisfied With The Product contact Us.