Sometimes referred to as the Sturmpanzer II Bison, the 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) was a German self-propelled heavy infantry gun used during World War II.
The Panzer II Ausf B chassis was lengthened by 24 in, which required adding a sixth roadwheel, and widened by 13 in to better accommodate the gun while preserving its low silhouette.
The 15-centimetre sIG 33 gun, for which 30 rounds were carried, could traverse a total of 5° left and right and used a Rblf36 sight.
Twelve were built at the end of 1941 and shipped to North Africa in early 1942 where they formed schwere Infanteriegeschütz-Kompanie("Heavy Self-propelled Infantry Gun Company") 707 and 708. The former was assigned to Schützen-Regiment 155 and the latter to Schützen-Regiment 200, both part of the 90. leichte Afrika-Division. Both companies fought until the Axis surrender in Tunisia in May 1943.