Light anti-aircraft guns ZPU-1, ZPU-2, ZPU-4 and ZU-23-2 were developed by the Soviet Union and are still in use. 14.5-mm anti-aircraft guns ZPU entered service in the early 1950s. There are three variants on different carriages: single-barreled ZPU-1, double-barreled ZPU-2 and four-barreled ZPU-4. The Chinese-made versions of the ZPU-2 and ZPU-4 are the Type 58 anti-aircraft guns and the Type 56 anti-aircraft guns, respectively. The ZU-23-2 23mm twin-barreled anti-aircraft gun was developed in the 1950s and armed with the Soviet Army in the 1960s. ZU-23-2 guns and the ZPU family significantly improved the air defense capabilities of the Soviet/Russian ground forces at low altitudes. These four powerful weapons have a high rate of fire and play an important role in low-altitude air combat and suppression of lightly armored ground targets. Due to their light weight, ease of operation and low cost, they are widely used by many armed forces as fire support weapons, especially in hot spots in Africa and the Arab world. They can also be easily mounted on various platforms as highly effective mobile fire support weapons.
