A. Improved Warm-keeping Design The upgraded heating insoles are made of imported heating wires, which can keep feet warm in cold weather and distribute heat evenly, promoting blood circulation in the feet. B. Safe and Efficient The products heat up relatively quickly, with relatively high and stable heat transfer efficiency and are relatively safe. The heating insoles made of carbon fiber heating wires provide uniform warmth, offering a warm-keeping experience. C. Easy to Use The insole heaters are washable. It is advisable to ensure they are dry before use. There are three heating modes: USB interface, power supply, and mobile power supply. Just put on shoes and connect the power supply, and one can enjoy the warmth. D. Adjustable Size The heating insoles can be cut and come in two sizes, ranging from 35 - 40 and 41 - 46. One can adjust them to a suitable size according to the foot shape, and specific sizes can also be customized. E. Suitable for Skiing and Other Winter Outdoor Sports