Endura Thermolite Leg Warmers are made from soft, insulating Thermolite fabric. The brushed fleece interior provides excellent insulation and wicks away moisture. Because of Thermolite's hallow-core technology, it has a low weight to insulation ratio, which translates into more warmth with less bulk. An 8" locking zipper allows easy removal over shoes and silicone gripper at the ankle and upper thigh keep it firmly in place.