The Sturm-Infanteriegeschütz 33B was a German self-propelled heavy infantry gun used during World War II. A new, fully enclosed, and heavily armored boxy casemate superstructure was built on the chassis of the Sturmgeschütz III. It mounted the improved sIG 33/1 infantry gun, offset to the right side, for which 30 rounds were carried. It could only traverse 3° left and right, elevate 25°, and depress 6°. A Maschinengewehr 34 machine-gun was fitted in a ball mount on the left side of the superstructure with 600 rounds. Its traverse limits were 15° left and 20° right, and it could elevate 20° and depress 10°.