The WXL Silver socks feature a material blend that releases silver ions, which effectively neutralize odors. The generous merino wool content already reduces odor issues from the start. This thinner sock model works well as a liner sock or can be worn alone with snug-fitting shoes. - Double-layer material at the heel and toe - 70% merino wool - 10% X-static synthetic fiber - 13% PAD (polyamide) - 7% Lycra - Koot: - S = 34 - 37 - M = 38 - 41 - L = 42 - 45 - XL = 46 - 49 Like all other Scandinavian Outdoor Merino wool products, this is a mulesing-free product.