Our heated socks made from super soft and thick material and with 19.7in length in total, are ideal gifts for your families and friends to keep their feet warm in chill winter! The socks are APP controlled so that you can adjust 113-167℉ heating temperature, 15-30-45-60-90Mins timer or set constant heating as needed via the APP. It can heat up fast within 20 seconds to warm your front instep, front sole (and toe/optional). Comes with 2Pcs 5000mAh battery packs, great to keep your feet warm about 3.5-7.5 hours according to different heating levels. Perfect for a wide range of activities, such as winter hunting, ice fishing, skiing, and so on.