1. Improved Warm-keeping Design The upgraded heating insoles are made of imported heating wires, which can keep your feet warm in cold weather and distribute heat evenly, promoting blood circulation in your feet. 2. Safe and Efficient Our products heat up relatively quickly, with stable heat transfer efficiency and are quite safe. The heating insoles made of carbon fiber heating wires provide uniform warmth, offering a good warm-keeping experience. 3. Easy to Use The insole heaters are washable. Please ensure they are dry before use. There are three heating modes: USB interface, power supply, and mobile power supply. Just put on your shoes and connect the power supply, and you can enjoy the warmth easily. 4. Adjustable Size The heating insoles can be cut and come in two sizes, ranging from 35 - 40 and 41 - 46. You can adjust them to a suitable size according to your foot shape, and specific sizes can also be customized. 5. Suitable for Skiing and Other Winter Outdoor Sports