Heat Sock 4.1 Toe Cap® is a pair of heated socks with integrated heating elements that warm both the top and bottom of the toes to keep feet warm. The elastic calf section ensures a good fit even for larger calves, and the comfort cuff keeps the socks in place without slipping. They are anatomically knitted for left and right feet and feature ring bandages for optimal fit. Padded reinforcements protect toes and heels. Natural merino wool combined with technical fibers wicks moisture and retains warmth. The lithium battery, attached via snap buttons to the comfort cuff and sold separately, is controlled either by pressing a button or via a free smartphone app.