MEN'S : Crafted of the most luxurious materials, including superfine Merino wool, to provide natural temperature control and moisture management. These socks are designed to create the perfect walking system when worn with Mephisto Footwear. 30% Merino Wool, 30% Bamboo Rayon, 35% Stretch Nylon, 5% Spandex. SIZING: Medium/Large (Women's shoe size 9-12 or Men's shoe size 7-10), Large/Extra Large (Men's shoe size 11-14).