The Heavy weight wader sock blends a Modal fiber which wicks moisture away from the foot with a Merino wool and Thermolite blend which provides added warmth and comfort. Improved durability through reinforced nylon on toe, heel and upper. Merino wool and Thermolite blend for comfort and warmth. Modal fibers wick moisture away from feet Ideal for cold weather use in wader boots. Constructed with antimicrobial material designed to fight odors. Full cushion foot reduces impact. Flat toe seam prevents irritation. Thermolite 50%, Nylon 17%, Merino Wool 10%, Lenzing Modal, Stretch Nylon 8%, Elastane LYCRA 3%, Acrylic 3%.