The 57mm GMC T48 was a very similar design ot the 75mm GMC M3. This vehicle, the pilot T48, is armed with the short barrel 6 pdr Mark III. Production vehicles were fitted with the American version of the 6 pdr Mark V, which had a longer and thinner barrel than the weapon featured here. This half-track has the fender-mounted headlights, the armored windshield is folded down, and the box on the running board housed batteries. The ruler in the photograph is 73" (185cm) tall. (Picture from Standard Nomenclature List G-102.)