M4A1 was a major US Medium Tank M4 with a molded, cast turret and a Continental R-975, 350 hp radial engine. Production started in February of 1942 and ended in January 1944. US factories released a total number of 6281 M4A1 tanks. Initially, the front hull had peepholes, but designers later decided to remove them. Covered gear compartment models of the early versions were made from three parts, later these were replaced with a cast single part. The main, 75mm gun M34 was replaced by M34A1 gun in 1943. From February 1942 to autumn 1942 the US arms industry produced around 900 M4A1 (early release) vehicles, that took part in the battles in Africa and Italy in 1942-1943.