Weapon Stats:

ZSU-23-2 23mm AA Gun

South Africa captured huge quantities of Russian weapons and equipement during operations into Angola during the Bush War.

The ZU-23-2 is a Soviet towed 23 mm anti-aircraft twin autocannon. ZU stands for Zenitnaya Ustanovka - anti-aircraft mount. This Russian anti-aircraft gun was used by 120 Squadron of 250 ADAG.

The weapon was also mounted on the backs of SAMIL100's and were called Zumlacs and are used by the Recce squadron in Durban at the Bluff.  

From Wikipedia:

It mounts two 2A14 23 mm autocannons on a small trailer which can be converted into a stationary mount for firing the guns. While in this position the wheels are moved aside. The autocannon can be prepared for firing from the march position in 30 seconds and in emergency can be fired from the traveling position. The weapon is aimed and fired manually, with the help of the ZAP-23 optical-mechanical sight which uses manually entered target data to provide limited automatic aiming. It also has a straight-tube telescope for use against ground targets such as infantry as well as unarmored or lightly armoured vehicles. The ammo is a feed by a conveyor belt from two ammunition boxes. Each of the ammunition boxes are located on the side of the twin autocannon and each carries 50 rounds. The fumes created by firing the weapon are partially removed thorough the side openings in the barrels.