The FlaK 38 (Flugabwehrkanone 38) was a 20 mm anti-aircraft gun widely used by various German forces throughout the Second World War. FlaK 38 and its predecessor FlaK 30 were produced by Rheinmetall and Mauser in large quantities (the base design of the gun was made by Solothurn, Switzerland). It was the primary German light anti-aircraft gun and was produced in a variety of models, notably the Flakvierling 38 which combined four FlaK 38's onto a single carriage.