Electric heated socks equiped with 2 battery boxes, each battery box powered by 5000mah batteries , heating time up to 5 hours. The battery on these electric socks is easily removable, so the heating sock is very esay to wear.Heating elements of the battery heated socks are made of insulated material, no worries about heating safety. Heating wire is so fine that your feet almost can not feel it. Comfortable heating temprature lets your feet no longer be cold and stiff in the cold winter.