Crafted to handle the harshest winter elements, the men's Butte pairs understated style with stay-dry technology. Cuffable, waterproof full-grain leather and ballistic nylon are finished with an exclusive Vibram outsole with repeating-lug pattern. An eVent membrane and moisture-wicking sheepskin lining offer the warmth and dry comfort characteristic of classic UGG. Waterproof Designed to help protect against heavy weather conditions, including water, rain, and snow. If present, zippers and tongues are gusseted and treated with water-repellent coatings. Weather Rated to -20ºC Cold-weather styles with this icon are rated for temperatures as low as -20°C (-4°F). Sheepskin Lining Vetted through extensive, industry-leading processes to ensure only the highest quality sheepskin makes the cut, delivering the signature feeling of UGG.