The StuG III series of combat vehicles was based on the lower hull of the Pz.Kpfw. III and featured a fixed upper superstructure. The design of the StuG allowed it to be quickly upgraded with the 7.5cm L/43 and shortly thereafter the excellent 7.5cm StuK40 L/48 which turned it into one of the best tank killers of the war. Since the roll of the StuG had quickly changed the infantry were left without direct fire support. To fill this gap it was decided to mount a modified version of the 10.5cm le F.H. 18 howitzer in the StuG III Ausf. G.
This version was designated 10.5cm Sturmhaubitze 42 Ausf. G or StuH 42 Ausf. G for short. The StuG and the StuH are virtually identical with the exception of the gun, gun sleeve and ammunition storage. The StuH 42 provided much needed fire support for the infantry yet it still retained some anti-tank capability through the use of hollow charged 105mm shells.A ratio of 7 StuG to 3 StuH vehicles in each Battery was viewed as correct, but seldom possible.