Features merino blend hiking socks 73 merino wool 25 nylon 1 elastane 1 polyester wow wool on wool technology a double layer of wool in cushions the heel flat knit toe seam reduces rubbing elasticised arch brace for lasting shape and a secure fit smartwool size guide size uk euro small 2 45 34 37 medium 5 75 38 41 large 8 105 42 45 x large 11 135 46 49