A great riding sock is different things to different riders. This carefully selected line of wool socks offers an ideal choice for fit, function, performance and all-day comfort from your footwear. In addition they are good for the environment too by using Nanoglide, a material created with recycled PTFE plastics. The Trekking Mid Wool sock is a comfortable mid-length 69% Wool, 7% Nanoglide sock. M(7-8.5), L(9-11), XL(11.5-13.5).