ZSU 57-2 AA SP Gun
From 1955 to 1974 this AA tank, based on the T54 chassis and mounting two 57mm autocannons as the primary low to medium height AA umbrella for armoured formations, and it was taken up by all of the Warsaw Pact Countries (other than Czechoslovakia) and was widely used by client states in the Middle East, particularly Egypt, as well as North Vietnam. In fact this AA system is still in use in many countries, with over 2000 built.