• High-quality thermal insoles that ensure even heat distribution. • Perfect for keeping feet warm in winter. • USB connection to quickly heat the insoles. • Suitable for men and women, can be trimmed to size. • EVA elastic fiber material with good cushioning properties. • No battery, generate heat only when connected. • Washable, must be completely dry before use. • Suitable for cycling, skiing, and outdoor activities in winter. • Precautions: Disconnect the power cable when not in use, supervision for the elderly and children.