Panzer III
Panzer IV was designed alongside the Panzer III. The Panzer IV was a slightly larger and heavier tank, and with its large calibre low velocity gun, it was designed to support the Panzer III when it met heavy resistance from infantry support. Pre-war production was 211 tanks. Originally armed with a low-velocity 75 mm L/24 gun, in 1942 this was upgraded to a 75 mm L/43 gun, and 1943 to a 75 mm L/48 gun.