The Sturmpanzer (a.k.a. Brummbar or "Grizzly Bear") was developed by Alkett, who designed the superstructure, and Krupp, who modified their PzKpfw IV chassis to accommodate the design changes. After seeing Alkett's plans on October 20, 1942, Hitler demanded that forty to sixty production models be built as quickly as possible. The first production run began in April 1943 and continued until the end of the war. The Brummbar had a box-like superstructure, which housed a huge 15cm StuH43 L/12 gun. The first series of Brummbars had a sliding shutter visor for the driver, similar to the one conceived for the Tiger I heavy tank. Newer production models featured a driver-side periscope, a ball-mounted machine gun mounted in the top left-hand corner of the front plate, and a cupola for the commander. This particular Brummbar comes with schurzen side armor skirts. Sold Out!