The Mil-Spec Sport Sock shares specifications with U.S. Military socks: they're built with anti-microbial silver filament yarn. The silver knit into the heel, toe and sole is proven to kill bacteria and promote moisture migration. The silver is game-changing. These socks are tough.
American Trench made a slight change to their "Mil-Spec" design, adding a compression band on the foot for additional performance, comfort, and arch support.