3.7 cm Flak 18/36/37

The 3.7 cm Flak 18/36/37 was a series of anti-aircraft guns produced by Nazi Germany that saw widespread service during the Second World War. The fully automatic cannon was effective against aircraft flying at altitudes up to 4,200 meters and was built in both towed and self-propelled versions. Germany also used the weapon in ground support roles under its flexible anti-aircraft doctrine. Production ceased with the German defeat, and 37 millimeter caliber anti-aircraft guns gradually fell out of use, replaced by the Bofors 40 mm gun and later by 35 millimeter anti-aircraft pieces produced in Switzerland.