Single, wheel mounted, used by the US and the German Armies. Developed in Sweden in the 1930’s. This particular one was manufactured by Goodyear Tire & Rubber in 1943. This gun is ideally suited to engage WW II low-flying, high-speed enemy aircraft such as dive-bombers and attack aircraft. In case of overheating, the barrel can be replaced in approximately 2 minutes. STATS - Maximum range: 7,500 yards, Rate of Fire: 120 rounds per minute. Two of these are on display. These pictures are from a military vehicle museum the American Society of Military History based in South El Monte, CA. These pictures are Copyright 2009.