The Darn Tough Hiker Boot Socks are built to withstand the rigors of the trail and provide cushioned comfort. This humble sock is an all-weather sock which is naturally antimicrobial and provides added protection and warmth. It is made of 64% Merino Wool, 33% Nylon, and 3% Lycra® Spandex. It includes features like fine gauge knitting, fast action wicking, and True Seamless ™ construction. All Darn Tough socks are made in Vermont, USA and carry a lifetime guarantee.