The M-55A triple 20mm anti-aircraft gun was introduced in Yugoslavia in 1955 and used against United Nation forces deployed to the former republic with the United Nations 1991 to 1996, particularily in the area of Sarajevo.
Later versions had an attached generator to provide power traversing and a more sophisticated computer assisted sight system. The gun is a daylight, clear weather only system. There is a self-propelled variant mounted on a BOV wheeled armoured vehicle. The gun was exported and remains in service with the military forces of the nations formed from the Former Republic of Yugoslavia and Tunisia.
Projectile: .142 kilograms (.313 pounds)
Range: 5,500 metres (6,015 yards); AA 2,000 metres (2,185 yards)
Detachment: gun, towing vehicle and 6 gunners