The Mark I weighed 63 tons. It had 900 horsepowers and the maximum speed was 46 km/h. It was armed with a 105-millimeter M64 main gun, and the M68 was later installed. Coaxially with the main gun, a 7.62 mm machine gun was mounted; the turret featured two more 7.62 mm machine guns as well as a 60 mm mortar mounted externally.