Socks that really do something about odor and moisture! X-System silver nonoparticles are highly effective in controlling odor. Silver has proven effective in many fabrics worn by members of the armed forces and law enforcement, and is used as an effective treatment in a variety of medical applications. In combination with moisture-wicking Coolmax fabric, this sock stays remarkably fresh and dry. Reinforced toe and heel. Made of 35% cotton/35% Coolmax/17% nylon/10% X-System polyester/3% spandex.