Thorlos Unisex ULHO Ultra Light Hiking Padded Over the Calf Sock, Black, Medium 78% Thor-Wick COOL polyester, 18% Nylon, 4% Elastic Made in US Turn Inside Out-Machine Wash-Use Liquid Fabric Softner Cozy sock in CoolMax fiber fabrication featuring stay-put band for a no-slip fit Targeted impact zone cushioning in ball and heel