Designed to a 1936 specification, the StuG was initially an assault gun built on a PzKpfw III chassis that was intended for tough infantry support. It arrived in 1940 and soon grew in numbers up to over 9000 by 1945. The StuG had a low profile b/c it was turretless, the main gun built into the main structure. It had a 4 man crew and was cramped to the point that the German commanders spent a considerable time half out of machine exposed. But German commanders prefered to call their shots, so this really did not matter. There were 7 versions from A-G, the last being the most armored and lethal. All carried a 75mm StuK, but the latter models had StuK 40s vs StuK 37s. Armored skirting was added and structural improvements. The assault gun quickly became a potent tank destroyer and was often mistaken for a German tank, usually with the skirting, wrap around top armor, and painted camo as a PzKpfw IV. Although not very beautiful the StuGs were lethal and remained in combat until the end. It's intended replacement was the StuH 42 with 105mm main gun and more armor. An 88mm version was in the works too, but only made it to mock-up stage... in wood. Thank God!

This was just too easy to write from memory :)