Note: - Smart battery, after loading the battery, turn the switch on. Automatic heating, 8 minutes. Close for one minute, and work for two minutes. Automatic looping. No manual operation required. - When the battery box is on, it will work on and heat up. - When the light is off, stop heating. - Can be washed, can not be used hard, must be dried to continue to use. Package Included: - 1 Pair Heated Socks - 2 X Lithium Battery Box Features: - Color: Black - Fabric: Cotton + Polyester + Spandex - Power supply: 3 x AAA Batteries (Not include) - Fever Location: Instep - Function: Keep warm, sweat and breathe freely. - Gender: Unisex - Size: Approx. 30x21cm/ 11.81x8.27" - Very suitable for hunting, ice fishing, hiking and sporting events. - Electric warm socks, cotton material, breathable - Water absorbent, quick-drying, elastic thickened, electric modules using ultra-thin, soft. - Electric heated socks for chronically cold feet. - Cushioned strengthened rear area and toe, and recessed warming component enable concentration to warm in the toe to shield your feet from getting cool - Battery powered, safe and reliable. - Built in heating elements extended along forefoot to promote blood circulation.