The ZU-23-2 (2A13) mounts two 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 T-3 for use against ground targets such as infantry as well as unarmored or lightly armoured vehicles. The ammo is fed by a conveyor belt from two ammunition boxes. Each of the ammunition boxes is located on the side of the twin autocannon and each carries 50 rounds. The fumes created by firing the weapon are partially removed through the side openings in the barrels.