Lightweight with Cushion - Light and strong with a thin layer of cushioning along base of foot. Our most versatile construction. True Seamless technology allows for an undetectable seam fusion for an ultra-smooth, invisible feel. Mid-Calf Height - A go-to, working height that’s always ready to take on more. Composition - Knit with 56% Nylon 41% Merino Wool 3% Lycra Spandex. The fast action wicking pulls moisture away from skin, so no more sweaty, stinky socks. The soft, breathable merino wool has fast drying, all weather performance that keeps you cool in the summer and warm in the winter. Guaranteed for Life - If these socks wear, tear, or develop holes, Darn Tough will replace them. No strings. No conditions. Made in the USA with yarns from America and around the globe - Every pair of socks is knit in Vermont - the perfect testing ground for the finest premium all weather performance socks.