FoxRiver Field Pack Mid-Calf Boot Socks (Pack of 2) 65% Acrylic, 20% Merino, Wool Blend, 14% Nylon, 1% Spandex Made in US Medium weight Fully thermalined leg absorbs shocks and stops shoe irritation Half-cushioned sole absorbs shocks and adds warmth Contoured rib top holds sock in place to eliminate slippage Medium weight