The original Sealskinz 100% waterproof, windproof & breathable mid length sock. The inner lining is crafted from fine Merino Wool to insulate and regulate temperature making this perfect for use in colder weather 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 Comfort - flat toe seams prevent rubbing Comfort - Footbed padding reduces pressure and absorbs shock MaterialsOuter: 90% Nylon, 10% Elastane Membrane: Aquasealz Inner: 35% Merino wool, 35% Acrylic, 23% Polyester, 3.5% Elastane, 3.5% Nylon