Features 1. High-quality material: heat insoles are made of flannel, carbon fibre heating blade and insole material EVA. Thermal soles that provide the warmth of everyday life and are ideal for keeping your body warm when the temperatures get cold. 2. Safe and efficient: heating is stable, safe and reliable. The carbon fiber heating wire heats the insole, the heating is uniform, the heat transfer efficiency is high, the heating speed is fast, and it is soft and comfortable. 3. Size information: thickness: 5 mm. Size: 35-46 (suitable size can be cut to size). Normally, shoe heating can be washed with water, best USB cannot submerge in water and use after drying. 4. 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. 5. Widely used: any kind of winter sports (skiing, snowboarding and etc.), working in the cold room or outdoors on cold days for polices and rescues personnel and more, cycling in the outdoor area, cold in the household and etc. Specification Material: EVA, Flannel, Carbon fiber heater Size: 35-46 Color: Black Weight: 165 g Package Included: 1 Pair x Heated Insole 2 x USB Charger