No more cold feet! This pair of socks contain 80% cotton which make your feet will stay nice and dry. Using thin but strechy adavanced heating solution, you can hardly feel the wire but only the soft and warmth of the material around your toe area. More over, new battery with larger capacity 3500mAh can provide longer continous warm than other vendors. Design and heating solution can be customized as per your request. Contact with us for more details.