The mark IV assault gun is based on the undercarriage of the STuG III with improvements proposed by General Guderian. These improvments include inter alia front armour plating reinforced from 50mm to 80mm, a longer front end and lateral aprons for additional side protection. Some 1,000 units were produced in 1943 and 1944. Crew: 4 men; weapons: one 75mm gun and one 7.92mm MG; engine power: 300hp; speed:38 km/h. This self-propelled assault gun was deployed succesfully in all war theatres.