The PT-76 is a Soviet amphibious light tank which was introduced in the early 1950s (N.E ?) and soon became the standard reconnaissance tank of the Soviet Army and the other Warsaw Pact armed forces. It was widely exported to other friendly states, like India, Iraq, Syria, North Korea and North Vietnam. Overall, some 25 countries used the PT-76. The tank's full name is Floating Tank–76 (Плавающий Танк, Plavayushchiy Tank, or ПТ-76). 76 stands for the caliber of the main armament: the 76.2 mm D-56T series rifled tank gun. The PT-76 is used in the reconnaissance and fire-support roles. Its chassis served as the basis for a number of other vehicle designs, many of them amphibious, including the BTR-50 armored personnel carrier, the ZSU-23-4 self-propelled antiaircraft gun, the ASU-85 airborne self-propelled gun and the 2K12 Kub anti-aircraft missile launch vehicle. It is used by the Coalition of Independent States