Pakistan purchased a batch of Type PG99 (CS/SA1) anti-aircraft guns from China’s POLY Group in 2011.
This type of anti-aircraft gun, which is also used by the PLA Army, was upgraded from GDF-02 that China imported from Switzerland in the earlier years.
Mounted on a 6 x 6 truck, the PG99 CS/SA1 is a self-propelled variant of the Type 90 35 mm AA system, previously available only as a towed AA piece. The system is based on a licensed Oerlikon GDF-002, and is credited with a 1175 m/s muzzle velocity, 3200 metre effective range, and 2 x 500 rounds/min rate of fire, with 360° traverse and +92° to -5° elevation.
The CS/SA-1 is suitable for point and coastal air defence. It is usually deployed near military bases, airfields, tunnels, islands, and along the coast to defend Sea Land of Communication (SLOC), ports, bridges and other important assets.
Sources: Kanwa Asian Defence (December 2012)
Air Power Australia ; Jane’s Internation Defence Review