In in the later years of World War II the Wehrmacht found they could no longer count on air superiority on any battlefield.
So a weapon was needed that could provide effective ground based fire, to keep those pesky jabos away…
Even before the War the Wehrmacht had expected aircraft to be a nuisance to the ground army. So right from the start Germany had anti-aircraft weapons attached to every formation. Much more so than other armies at the time.
But these weapons were not really modernized for quite some time, largely because the Luftwaffe so often held air superiority or outright aerial supremacy. Well into 1942 the anti-aircraft component of the military was changed little. But by 1943 the battlefield was changing. British, American and Soviet air forces all were becoming practiced in close support work and could often force local air superiority.
Mobile anti-aircraft was increased to compensate, as well as it could. But what was really needed was something that could aggressively face enemy tactical aircraft. Obsolete armor platforms [mainly Panzer III and 38(t)] were being retasked as tank destroyers already. By mid-1944 even the Panzer IV was past its prime as a main battle tank, so it was decided to convert a number of these into dedicated anti-aircraft platforms. As a bigger tank it could support an effective quad 20 mm mount, plus moderately thick turret armor, and ample ammunition. It also had modern communications and targeting optics. Around 100 Panzer IV were converted to Flakpanzer IV Wirbelwind specification (exact numbers not known).
Its effectiveness was mixed. Quad 20s were viciously useful against soft ground based targets, like infantry, trucks and recon vehicles. But the fire was too light and too short range for anti-aircraft. Of course a 20 mm cannon can do significant damage to an aircraft, but aircraft are small and fast moving. They are more often brought down by volume of fire than by a few well placed shots (targeting them is a low percentage shot). The 20mm is too short range and has a very limited window of opportunity.
So a new weapon, the Ostwind (similar looking Panzer IV conversion but with a single 37 mm cannon) was designed by the end of 1944. This was a slightly more effective weapon but Only 44 of these were finished by the end of the War.
This is the Tamiya kit. It represents a vehicle captured in France at the end of the war, no unit assignment was noted.