Flakpanzers based on the Panzer IV

The Möbelwagen (furniture wagon) was the first attempt to mount an anti-aircraft gun on the chassis of a Panzer IV tank.
The Wirbelwind (Whirlwind) was the second production vehicle to mount an anti-aircraft gun on the chassis of the Panzer IV tank.
The Zerstörer 45 was a more powerful version of the Wirbelwind Flakpanzer, designed to compensate for the relatively low power of the quadruple 2cm guns used in the earlier vehicle.
The Ostwind I (East Wind) was the last of a series of Flakpanzers (anti-aircraft tanks) based on the Panzer IV chassis to enter production, albeit in very small numbers
The Ostwind II was a further development of the Ostwind I Flakpanzer, which would have carried twice the firepower, but that never progressed beyond the prototype stage.
The “Kugelblitz” (Ball lightning) Flakpanzer would have been the most advanced anti-aircraft tank produced by Germany during the Second World War if it had ever entered production, but the first prototypes did not appear until 1945, and it never entered combat