A new version, based on T-54A, designated T-54B (Object 137G2), was designed in 1955. It was fitted with a new 100 mm D-10T2S tank gun with STP-2 "Tsyklon" 2-plane stabilizer. It entered production in 1957. During the last four months of production, the new tanks were equipped with an L-2 "Luna" infrared searchlight, a TPN-1-22-11 IR gunner's sight, and an OU-3 IR commander's searchlight. Modern APFSDS ammunition was developed, dramatically enhancing the penetrative performance of the gun to keep it competitive with NATO armour developments. T-54B served as the basis for T-54BK command tank, which had exactly the same additional equipment as the T-54AK command tank.
