The original Sealskinz 100% waterproof, windproof and breathable mid length sock. The inner lining is crafted from fine Merino Wool to insulate and regulate temperature making this perfect for use in very cold conditions. Waterproof - three layer construction for warmth, durability and waterproofing Comfort - Merino wool lining for moisture control, insulation and comfort Support - zonal elastication for added support Close fit - four way stretch for comfort and stretch fit Anti-Blister - Prevents friction and rubbing which eliminates blistering Comfort - Footbed padding reduces pressure and absorbs shock MaterialsOuter: 90% Nylon, 10% Elastane Membrane: Aquasealz® Inner: 41% Merino wool, 41% Acrylic, 14% Polyester, 2% Elastane, 2% Nylon