The next prototype, the A4E20, numbered MT7984 (or Light Tank Mk.II Indian Pattern No.1/L2E2), had a slightly modified body. The sights were improved, with new slits placed at better angles, and the design of the exhaust pipe and side niches was changed. The most important innovation was the standardized four-sided tower of increased size, protected by 9 mm (0.35 in) of armor. Elevation for the machine gun was raised to -10 to +37 degrees. A water tank was mounted just under the roof, to cool down the machine gun. This new experimental model was demonstrated once more to the RTC, which in 1933 decided to conclude a contract to produce a small batch under the ordinance designation Light Tank Mk.IV.