Style #1931 Heat on the trail comes in many forms. From hot and humid to dry and searing to just plain old mean and nasty. This Coolmax air conditioner of a sock offers cooling comfort on even the balmiest of days. Machine Wash Coolmax Engineered to move moisture away from your skin and dry fast in warm conditions. The perfect sock for runners looking to lose bulk without sacrificing cushioning and comfort when the weather gets hot True Seamless construction reduces hotspots and blisters Still made in Vermont, USA Unconditionally guaranteed for life 37% Nylon, 34% Coolmax Polyester, 26% Acrylic, 2% Lycra Spandex, 1% Other fiber True Seamless Undetectable seam fusion for an ultra smooth, invisible feel. These socks won't stop global warming, but you might not mind quite as much. Coolmax Polyester yarns are engineered to move moisture away from your skin, to be fast drying and to enhance comfort. Legendary Darn Tough construction and performance fit assure that socks stay put and in place all day. No slipping. No bunching. No blisters. No hot spots. Cushioning on the foot base provides comfort and fit with the perfect bounce that hikers and trail runners love. Stay cool, keep hiking. Still made in Vermont. Guaranteed for life.