The Gerbing 7-V heated sock liners are battery powered socks that keep the feet warm for 5-7 hours in low temperatures offering ultimate warmth and comfort during winter activities. Powered with the two 2200 mAh batteries and the advanced patented Microwire heating technology, these electric socks can be an excellent choice for winter foot warmers for men and women. Made from lightweight, stretchable, heat-insulating, and moisture-wicking fabric—polyester and spandex, Gerbing heated socks ensure that you get heat at the top and bottom of your foot. These socks have special long-cut pulls over your calf to fit any boot or shoe. The even distribution of heat is possible due to the patented Microwire heating technology that makes it suitable for various winter sports, hiking, cycling, camping, skiing, and others. With the touch-button control, users can set the temperature of the electric rechargeable battery-operated heated socks in three modes—High (140 F for 3 hours), Medium (120 F for 5 hours), and Low (100 F for 7 hours). You will love these versatile socks that keep your feet warm for 7 hours. You also get 2 Gerbing 7V sock liners, 2 Gerbing 2200 mAh batteries, 1 Gerbing 7V dual charger, and a Gerbing lifetime warranty.