The designation M4A1 was applied to the M4 medium series to use an one-piece cast hull with a distinctive round shape. The up gunned M4A1 to mount an 76mm M1 high velocity gun and a T23 turret was different from the early M4A1 hulls as the hull front now spots two large hatches for the driver and the co-driver. The tank also had wet storage protection for the ammunitions hence the designation with the "W". At first these tanks were not welcomed by the troops but they were used with success in the Operation Cobra following the D-Day invasion. The very early M4A1 (76)W had some minor differences to the later standard type. The kit can build to depict these early machines.