70% Merino Wool, 25% Polyamide, 5% Elastane. The Silca Winter Sock is made with the same modern Italian knitting machines as the Everyday Aero Socks. By using Merino wool, the toe box has extra padding (perfect for absorbing water and sweat) without increasing the thickness of the heel, which can alter the fit of your shoes. The sock has strong compression, so if a looser fit is desired, one size larger should be chosen. Product Details Article Color name grey Gender Unisex Size (D) 39.0 , 39.5 , 40.0 , 40.5 , 41.0 , 41.5 , 42.0 Size International M Main color grey Season Winter Type mid-high