MADE IN THE USA: Knit on the grounds of the historic woolen mill in Ashland New Hampshire USA, these socks are Comprised of 61% Merino Wool, 24% Nylon, 14% Stretch Nylon, 1% Spandex DURABLE AND BREATHABLE: The mountain heritage collection are knit to maximize merino wool against the skin with added nylon on the outside in the highest wear zones of the sock for high durability and exceptional breathability PERFORMANCE FIT: Designed to comfortably fit the shape of the foot to prevent slipping, bunching, and blisters. QUICK WICKING: Thanks to a high Merino wool content these socks quickly wick moisture away from the skin and are fast drying.