The 2cm FlaK 38 was a variant of the earlier FlaK 30 naval gun developed by Rheinmetall-Borsig from the Swiss Solothurn ST-5. The FlaK 38 was to have a greater rate of fire with improved ammunition feeding, though the 20-round box magazine was retained. The rate of fire (practical) was raised from 120 rpm to 220 rpm, while the overall weight of the weapon was lowered. With a muzzle velocity of 900 m/s, the FlaK 38 had a range of 2,200 meters.

In 1940 the 2cm Flakvierling (quad mounting) 38 was officially adopted by the German army as its standard light anti-aircraft weapon. Mauser was made responsible for the development work and subsequent production of this variant. All four guns could be fired with a combined rate of fire of 800 rpm, or the weapons could be fired in pairs.

During the war it was used either vehicle mounted or on its familiar 4-gun Sd.Ah.52 towed carriage. As the war progressed, ammunition was developed for ground use against vehicles and ground works.