Their Mohair / Nylon blend hits the sweet spot of glide and grip, and they're sealed with vulcanized rubber for waterproof performance when things get warm and slushy. Use your head, grab the Karakoram Smart Skins! Waterproof Sealed with Kohla’s Patented PFC-free Vulcanized Rubber. Prevents water absorption. Keeps skins sticking to ski base in Spring conditions.