1. Features: - Material: Cotton + Carbon fiber - Dimensions: (Flexible) Sole length: 20 cm; Sock length: 23 cm; Sock opening: 9 cm - Battery voltage: 3.7 volts - Battery capacity: 2200 - 4500 mAh - Temperature control: 3 - level adjustable - Temperature: Low - temperature setting: 35 degrees Celsius; Medium - temperature setting: 45 degrees Celsius; High - temperature setting: 55 degrees Celsius - Color: Grey, Black - Quantity: 1 pair - Package contents: 1 pair of heated socks (with battery and charger) 2. Battery operation - Enlarged heating elements: To keep feet warmer and more evenly, the heated socks have enlarged heating elements in the toe and sole areas. Once fully charged, they can keep feet warm for a long time. - Note: During charging, the adapter indicator light shows red, and turns green when fully charged. 3. 3 - level adjustable temperature - The electric heated socks have 3 - level temperature adjustment, with a heating range from 35 degrees Celsius to 55 degrees Celsius. The red LED light corresponds to the high - temperature setting, the orange LED light corresponds to the medium - temperature setting, and the green LED light corresponds to the low - temperature setting. 4. Flame - retardant safety cotton - The heated and warm - keeping socks are made of cotton, polyester fiber, and spandex. This breathable, quick - drying, and specially developed flame - retardant cotton cloth allows for more worry - free use. Moreover, the far - infrared heating elements of these winter socks can promote blood circulation. They can be good gifts for people with arthritis in their feet and those afraid of cold joints. 5. Washable and one - size - fits - all - The battery of the heated socks supports both hand - washing and machine - washing. Note: Please put the charging cable inside the sock before washing. The heated socks are suitable for both men and women in a one - size - fits - all way. It has good elasticity and stretchability for adults, men, and women. 6. Wide range of uses and good gifts - The electric heated socks are suitable for various indoor or outdoor activities, such as hunting, hiking, horseback riding, fishing, cycling, driving, running, camping, skiing, mountain climbing, sleeping, etc. The heated skiing socks can also be good gifts for parents, friends, family members, and the elderly.