Anyone who skis uses skins. Originally made from seal skin and attached to the bottom of skis, used for skiing up hill. The pattern of the hair flows to the reverse, so you can easily slide the ski forward and don't slip backward, even on steep slopes and while wearing a pack. "Skins" are now made of mohair and still glued & strapped to the ski. Can't wait for the feds to make a raid on REI, Marmot Mountain Works and other mountaineering shops to confiscate their skins. Seal skin has not been used for ski skins in over 50 years!