Covert X-FIT Sock Content: 55% Polyester, 37% Nylon, 6% Polypropylene, 2% Spandex Our Covert X-FIT fights blisters, Hydro-Tec & Polypropylene move moisture away from skin, resilient cushioning in the Strike Zones-Exactly where you need it, allows the foot to breathe around the entire circumference of the sock, built-in arch support for those extra miles on your track, vapor mesh for lighter weight sock and better moisture release. Reinforcement of heel & toe makes sock last longer and helps protect your feet. Antimicrobial Silver Lining aids in odor protection and foot health. Blisters, wet skin, hot shoes, uncomfortable bulky socks --- no more! Features: * Soft Cushioned Strike Zones * Reinforced Heel & Toe * Moisture Wicking HydroTec Polyester Zones * Built-In Arch Support, Super Thin Breathable Body * Resilient Lycra Fit * Polypropylene Body Wicks Moisture with Low Body Weight-Quick Drying MADE IN THE USA OF US MATERIALS BY AMERICANS