The tank T-34-85 entered service on December 15th, 1943 and was further upgrading of the main combat tank T-34 of the Red Army. T-34-85 were sent for service to many armies of the world, took part in the combat operations in Korea(1950), Middle East(1956,67,73), Vietnam, Angola, Ethiopia and other hot points of the world. During the Vietnam War, the North Vietnamese Army was provided with small number of ZSU-57-2 air defence vehicles. To supplement these, small number of T-34-85 tanks were modified with a new turret mounting thr Chinese Type 63 twin 37mm guns.