speed trail stromper blaThis sock is a short thermal sock that can be used in the fall winter when you are training or walking a lot. It has an "X Cross System" which provides increased support, stability and reduces overload of the ankle ligaments. Size guide Size Shoe size Small 35 38 Medium 39 42 Large 43 46 Composition Washing instructions 42% Merino Wool 52% Polyamide 6% Elastane Wash at 40 degrees