The original, 100% waterproof, windproof & breathable knee length sock with insulation and temperature regulation, 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 Outer: OUTER: 90% Nylon, 10% Elastane Membrane: Hydrophilic Membrane Inner: INNER: 35% Merino wool, 35% Acrylic, 23% Polyester, 3.5% Elastane, 3.5% Nylon Merino Wool - Finer than traditional wool with tiny overlapping scales that case each fibre, these scales are hydrophobic (water repellent). Inside it\'s a different story, the fibre core is hydrophilic (highly absorbant). Merino is therefore a wicking fibre and can absorb and release 10 times more moisture than synthetics. Each fibre can absorb up to one third of its own weight in moisture without feeling clammy or wet to the touch. In our socks and gloves, the moisture is then wicked through the membrane to keep you feeling warm and dry