Darn Tough Vermont Men's Merino Wool Over The Calf Padded Ultra Light Socks Merino Wool, Nylon, Lycra Spandex 60% Merino Wool, 36% Nylon, 4% Lycra Spandex Made in Vermont, USA Unconditional Lifetime Guarantee Performance fit and Unsurpassed durability Men's Sizes: Small 5.5-7.5, Medium 8-9.5, Large 10-12, X-Large 12.5-14.5, XX-Large 15-17