The Merino Trekking Sock from Dexshell is a highly durable midcalf length, waterproof trekking sock. Suitable for trekking, hiking and other outdoor activities in arduous, wet conditions. The key features include a moisture wicking inner for maximum warmth and comfort combined with breathable technology for the avid walker. Size Chart     Small = UK 3-5 (EU 36-38) Medium = UK 6-8 (EU 39-42)Large = UK 9-11 (EU 43-46)X-Large = UK 12-14 (EU 47-49)   Outer shell: 96% abrasion resistant nylon, 3% elastane, 1% elasticInterlining: Porelle waterproof breathable membraneInner sock: 40% merino wool, 40% anti-pilling acrylic, 20% nylon