The German flak 43 was a ubiquitous automatic anti-aircraft gun that served in most theatres of WW2 with the Army Navy and Luftwaffe. It carried quite a punch and was rightly feared by Allied fighter bombers, one hit often being enough to down a fighter.
 
The 3.7 cm Flak 43 was a dramatic improvement over older models. A new gas-operated breech increased the practical firing rate to 150 RPM. It would be found on patrol craft with the Navy and was also employed in a ground role. Resourceful units would mount it in whatever vehicle could be found and used both in an anti-tank and anti-personnel role. Many 37mm Flak were also mounted on the ubiquitous Sd.Kfz 7 half-track vehicle and perhaps most famously were the conversion based on the Panzer IVs, first the "interim" Möbelwagen, and later the Ostwind.
 
The ground mounted Flak 43 comes with a seated gunner, and three other operatives, scanning the skies for prowling allied aircraft.