Product Description Material: Cotton + Carbon Fiber Size: (Elastic) Sole Length, 20cm; Sock Length: 23cm; Cuff: 9 cm Battery Voltage: 3.7 V Battery Capacity: 22004500 mAh Temperature Control: 3 Levels Adjustable Temperature: Low, 35C; Mid-Range, 45C; High-end, 55C Color: Gray Quantity: 1 Pair Package Contents: 1 Pair* Heated Socks 1. Battery Powered and Enlarged Heating Elements To keep your feet warmer, our heated socks have the following features Enlarged heating elements on toes and soles. Keep your feet warm all day long when fully charged. PS: The display of the adapter lights up red during charging and green when fully charged. 2. 3 levels of adjustable temperature The electric foot warmer has 3 levels of temperature, and the heating range of the electric socks is between 35C and 55C. The red LED corresponds to the high temperature setting, the orange LED corresponds to the medium temperature setting, and the green LED corresponds to the low temperature setting. 3. Flame retardant safety cotton heated thermal socks are made of cotton, polyester, spandex. Breathable, quick-drying, specially developed flame-retardant cotton makes you feel safe during use. What's more, the far infrared heating elements of winter socks can stimulate blood circulation. They make an ideal gift for anyone with arthritic feet and cold joints. 4. Washable, moderate size The heated socks battery supports hand wash and machine wash. Note: Please remember to put the charging cable in the socks before washing. Unisex heated socks, medium size. One size fits all, super stretchy and stretchy for adults, men and women. 5. Widely used and best gift Electric socks are perfect for various indoor or outdoor activities, such as hunting, hiking, horseback riding, fishing, cycling, driving, running, camping, skiing, mountaineering, sleeping, etc. Ski heated socks can also be an ideal gift for parents, friends, family members and the elderly.