Product Details Socks informationMaterial: 55% Coolmax, 25% Elastio, 20% spandex Size: S / M / L / XL Adjust the temperature gear: red light (high), white light (medium), blue light (low) heating time: 2.5-8 hours heating temperature: 40-65 C heating area: front foot / toe / sole. Heating element: far infrared heating element Suitable for: Skiing/ Cycling/ Motorcycling/ Hiking/ Fishing /Hunting / Outdoor Activities Product features [soft and breathable] warm socks are super comfortable, thick and well filled. They are absorbent, breathable, quick drying and elastic [warm, comfortable and healthy] heating socks are upgraded with far-infrared heating elements. Two carbon fiber heating pieces, soles, insteps and toes heat at the same time. Infrared can stimulate foot blood circulation. It is very suitable for people with arthritis, poor circulation, joint stiffness and chronic foot cold. [high quality imported materials] this winter sock has a long service life and is equipped with a 7.4v UL / CE certified 2200mAh lithium ion rechargeable battery. It adopts high-quality materials and dual cable charging system, which can charge the battery at the same time and facilitate the removal of the battery. [easy to control temperature] level 3 heating controller is set to adjust your favorite temperature. The controller LED red indicates high temperature, white indicates medium temperature and blue indicates low temperature