Climbing skins are strips that attach to the bottom of nordic skis to help while ascending backcountry slopes. They are designed to be removed for skiing downhill. They are typically attached to the skis via a loop on the ski tip and adhesive on the ski base. They are called skins because they resemble sealskin and are designed to let the ski slide forward on snow but not backward. They can be made from nylon or mohair. They are usually narrower than the ski to allow the ski edges to get a grip.