This is a pair of heated . Rechargeable heating, to solve the winter foot frostbite. Make your foot more comfortable and . Against the cold in the household. Heating elements deliver smoothing warmth. Heats entire surface area of your foot. Features - Color: Black - Material: fiber, far infrared carbon fiber, USB cable - Size (35-39): 25.00X8.50X0.50cm/9.82X3.34X0.20inch. - Size (40-44): 27.00X9.50X0.50cm/10.61X3.73X0.20inch. - Using materials, this product is durable, easy to use, and can be used for a long time. - processing ensures a comfortable touch. USB connection is very convenient for charging. - The USB interface is convenient for heating. Suitable for men and women. - Low-voltage power supply, safe and energy-saving. It is perfect for keeping your feet in winter. - The heating insole adopts a thin design, which has flexibility and can evenly distribute the heat on the surface of the substrate. Package list: 1 pair x heating 1 x USB cable