When StuG III production was affected following serious bombing of the Alket works, Hitler requested the StuG III superstructures be fitted to Pz Kpfw IV chassis. Thirty vehicles were produced from existing Panzer IV chassis. Krupp then halted production of Panzer IVs in December 1943 and switched to StuG IV production in January 1944. The StuG IV was armed with the 7.5cm StuK40 L/48 and was used in both infantry support and tank destroyer roles.