The M12's ordered were used for training purpose only. In 1943, with the invasion of Europe imminent, the US. Army decided to have the M12's upgraded for possible use in overseas theaters. The heavier suspension of the M4 with rear mounted return roller was used to modernize the vehicle. Baldwin Locomotive Works, the company updating the units, also mounted a small shield on the gun mount and removed the co-driver's hatch.

With an elevation of -3' to +35' and traverse capabilities of 28' to 14' the 155mm gun on the M12 carried ten rounds of artillery and had a maximum range of 15,200 yards.

A 353HP air-cooled Continental R975 radial engine yielded a maximum speed of 24mph. In June of 1944 they were send to Europe and used for several major battles including the taking of Cologne.

Accurately reproduced hull, 155mm gun and interior details.
Movable gun elevation and suspension.
Plentiful accessories.
Realistic flexible tracks.
Choice of open or closed hatches.