Features a wide elastic band with a Velcro® brand hook-and-loop strap for an adjustable, comfortable fit around your calves. Heating elements are located at the top of your foot then wrap around your toes and under your foot. Includes a y-harness to California Heat's heated Sock Liners are designed to be worn over a very thin sock, providing a comfortable fit while wearing your favorite footwear. With heating elements starting at your ankle then wrapping around your toes and under your foot, your tootsies are guaranteed to stay toasty. The socks begin warming your feet within seconds using a compact, rechargeable 7V lithium-ion battery. The advanced heating technology allows you to maintain a constant level of thermal comfort and protection while enjoying your favorite outdoor activities. Constructed of thin, lightweight Lycra® Spandex - moisture-wicking.