Sports Katz Plasma Crew Socks SM=child size or up to shoe size 6, ML= adult size or shoe size 7 or larger 58% Polyester, 24% Nylon, 11% Elastic, 5% Acrylic, 2% Spandex! Made in USA, Katz Exclusive! Athletic Socks. Dries twice as fast as cotton! Great team socks! Made in USA