Jadgpanzer IV was an improved and modified version of the Stug III, designed as an eventual replacement for it. In December of 1942, a new tank destroyer with 100mm frontal armor, armed with a 75mm Pak 42 L/70 gun, and based on PzKpfw IV was requested by the Waffenamt. The vehicle was to have a low silhouette with the main gun mounted in a superstructure. The new vehicle was known as Jadgpanzer E 39 and more commonly as Jagdpanzer IV. Work on its design took place in early 1943 and on May 13, 1943, Vomag produced a wooden mock-up, which was shown to Hitler in September of 1943. The main role of the new vehicle was to be a tank destroyer. The first soft steel prototype was ready in October of1943, which was then shown to Hitler as well. In December of 1943, the final prototype of Jagdpanzer IV was ready and Vomag was ordered to start production as soon as possible.