The Panzer IV was the only German tank to be produced throughout World War 2. As such, numerous design changes were proposed over the years. The gun tank appeared in in several versions. Ausf. A through F1 carried the 7.5cm KwK L/24 tank gun, the Ausf. F2 and G carried the 7.5cm KwK 40 L/43, while the Ausf. H and J carried the 7.5cm KwK 40 L/48. The Panzer IV also provided the chassis for numerous tank destroyers and assault guns. This page will focus on some of the variants which either only saw limited production, were only developed to the prototype stage, or never made it off of the drawing board (because of the restraints of time or practicality).