Thick tennis socks in a crew sock made with Thorlo's very own moisture management system: Thor-lon. Designed to provide you with the maximum shock protection during court sports. Features: Thor-lon - wicks the moisture away from the foot Thick cushion - maximum impact and blister protection and shear resistance Cushioning over the toes Flat knit at instep for better fit and support Materials - 88% THOR-LON® Acrylic, 10% nylon, 2% spandex Proudly made in the USA This is a Protection Level 3 crew sock designed to help protect your feet from the damaging effects of impact, shear and blistering common to playing tennis. This product provides the most protection available (beyond what any other sock can provide today) and may require a 1/2 size larger shoe. Wear this product when fitted with new shoes. Size Information (TX) Unisex Sizing USA Shoe Size Youth Women’s Men’s S 2-4 4-6 M 6.5-10 5.5-8.5 L 10.5-13 9-12.5 XL 13-15