Lorpen Tri-Layer Allround Trekker Crew Socks are designed funnily enough as an all round general purpose hiking, walking or whatever sock. Like all Lorpen socks they are very comfy and hard wearing, the Allround Trekker is a Tri-Leyr sock which has a cushioned sole and nylon knit onto high-friction areas for extra durability. Features 3 layer sock: 1. Hydrophobic (non-absorbent) polyester inside layer: These fibres, made of Coolmax, wick sweat away from your feet without absorbing it, keeping your feet dry 2. Hydrophilic natural absorbent middle layer: Tencel natural fibre absorbs your sweat from the inside and sends it to the outside of the sock where it evaporates more quickly over a larger surface area. 3. Nylon outer layer: The 'tough guy' of the fibre world, nylon is highly resistant to abrasion and is located in the high friction areas of the sock The advantages of the 3 layers: A dry foot reduces the chance of irritation that can be caused by hours of physical effort Helps regulate temperature, reducing the chance of 'hot foot' Incidence of bacteria is minimised because the sock stays drier on your foot LifeFit fit elements: Lycra throughout the sock avoids the slipping and bagging out that can happen with a sock over time Multi-density knit provides optimum cushioning and superior fit The mesh instep minimises bulk on the top of the foot and promotes heat and moisture release The flat knit toe seam avoids any irritation Content 50% Coolmax, 25% Tencel, 15% Nylon, 10% Lycra Size Guide Small fits UK 4-6 Medium fits UK 5.5-8.5 Large fits UK 9-11.5 Xtra Large fits UK 12-15