Mountain Hardwear Caelum Dome 100% Wool The multi-use hat can be used in a variety of winter sports, including snowboarding, alpine climbing, skiing and mountaineering. The stylish beanie comes in a wide range of colors, such as green, blue, turquoise and red. The recycled polyester microfleece lining keeps your head warm and comfortable. The eco friendly beanie's inner lining is made from recycled polyester microfleece. The outer body of the Mountain Hardwear Men's Caelum Dome is made from 100% wool, one of the most effective materials for trapping heat.