The 15 cm StuIG 33B was a German self-propelled heavy assault gun. In July 1941 the order was to convert a dozen Sturmgeschuetz III Ausf. E chassis into a heavy assault gun and that these were finished in December 1941 and January 1942. On 20 September 1942, another dozen Sturmgeschutz IIIs were ordered to be converted, and the existing vehicles were rebuilt. Most of them were lost in the battle of Stalingrad. The remainding vehicles were used by 23rd Panzer Division where it became the Sturm-Infanterie-Geschuetz-Batterie/Panzer-Regiment 201 (also known as 9. Kompanie/Panzer-Regiment 201) for the rest of the war. The last strength report to mention them lists five remaining in September 1944