FoxRiver Tatra Lite Over the Calf Socks 43% Nylon/26% PrimaLoft polyester/26% Merino wool/5% Spandex Made in US Made from PrimaLoft yarn and Merino Wool Helix Fit System includes volumetric compression Vented panels remove moisture and keep you dry Reinforced toe and heel add comfort and longer sock life Wick Dry Moisture Management Technology Made from PrimaLoft yarn and Merino Wool