The Under Armour Infil GTX features a breathable Gore-Tex membrane that is 100% waterproof but still allows sweat to escape, so you stay dry.  Cupron Anti-Fungal Pro Fibers kill 99.9% of athlete's foot fungus after 12 hours of contact with the sock liner.  The Cupron fibers also reduce odor caused by bacteria and fungi.  A rugged, Vibram MegaGrip rubber lug outsole is engineered for better grip through harsh terrain.