Product detailsColor Black,GreyMaterial 55% Coolmax 25% Elastic 20% SpandexPower Source Battery PoweredBattery Description Lithium IonSoft and BreathableHeating socks with super comfortable, thick and well padded.Absorbent, breathable, quick-drying, elastic-thicken, use ultra-thin electric heating module.Soft Padded reinforced heel & toe accurate stitching and recessed heating element help focus heat on the toe to keep your feet warm from cold weather.Warm Your whole feet in SecondsElectric breathable heated socks can stimulate poor blood circulation, keeping warm & toasty in seconds; the Advanced Technology of Far-infrared Fiber Heating Elements Covers Instep and Toes Area; 3 Levels Intelligent Temperature Control make it easy and safe to adjust your perfect heat. High: 99% power (140F/60C 2-3hours ), Medium: 66% power (113F/50C 4-5hours), Low: 33%power (95F/40C 8-9 hours)Various Size OptionAll Men, Women, Male, Female, Boys, Girls, Elders can wear the Battery Heated Socks to keep feet warm. S, M, L , XL . Size chart as following: S for size 5-6 foot ; M for size: 6-8.5 foot ; L for size:9-12 foot ; XL for size :12-14 foot . please check size chart pic on left .Quality Imported MaterialThis winter socks have long life work time with 7.4V 2200MAH Li-ion rechargeable battery.Imported heating elements and quality material.It can keep you warm all day (especially for chronically cold feet), Dual cable charging system for the batteries to charge at the same time, the ease of removing batteries. Long-lasting heating, long life batteries, no longer afraid of the cold.Suitabale for Winter OutdoorsOver the calf heated warmer socks are friendly with your ski boots; Coolmax, elastic, and Spandex material provides premium insulation performance while being midweight thickness and soft; the battery heated long socks are perfect for hunting, camping, skiing, skating, snowboarding, fishing, hiking, walking dogs, motorcycle, riding, office or outdoor working, etc.