Thicker than our Hot Weather Dress sock, Wigwam's Hot Weather BDU Pro helps your feet survive long days in tough boots. Our patented Ultimate technology combined with drirelease Tencel to provide fresh and dry comfort during maneuvers. US patent No: 5,095,548. 40% Polyester, 30% X20 Acrylic, 24% Stretch nylon, 5% Tencel, 1% Spandex.