Darn Tough Vermont Women's 1/4 Merino Wool Cushion Hiking Socks Merino Wool 65% / Nylon 31% / Lycra 4% Made in US 65% Merino Wool, 31% Nylon, 4% Lycra Spandex; Machine wash in warm water on gentle cycle with socks turned inside out. Do not bleach. Tumble dry on low. Do not dry clean. Custom shrink treated Merino wool holds its shape and wont shrink Reinforced heel and toe for a very long lasting sock Elastic arch support helps provide endurance for your feet United States