The first production units, the Sturmgeschütz III Ausf A, arrived in 1940 mounted with the howitzer-like 75 mm StuK 37L/24 gun and increased frontal hull armor (from 30 mm to 50 mm).[1] The main armament, which had a limited lateral traverse, was mounted directly in a casemate-style hull. This created the lowest possible profile in order to reduce the vehicle's height, making the StuG more difficult to hit and easier to protect in hull defilade.