The 2S6M Tunguska surface-to-air gun/missile system is a tracked combat vehicle which was designed to ensure 24-hour protection of ground troops against low-flying aircrafts and helicopters in all weather conditions. It is in service since 1990. It is armed with 30-mm cannons and 8 surface to air missiles of the type SA-19. The general layout of the vehicle is rather conventional, with the driver seated at front left, the turret with seats for the other three crew members in the center and the engine and transmission compartment at the rear. The cannons which used in the 2S6 are mounted in pairs. The SA-19 missiles are mounted four on each side of the twin 30 mm cannons and can be independently elevated. The 2S6 can engage targets flying at a maximum speed of 500 m/s (1,800 km/h). The Tunguska system has a reaction time of eight seconds. The effective target-tracking range of the complete system is from 0.2 to 10 km, while the maximum effective vertical kill range is around 8,000 m and 3,500 - 4,000 m of altitude. Although the weapons can be used when the vehicle is moving, a higher accuracy can be obtained when the system is stationary. The surveillance and target acquisition radar is mounted at the rear part of the turret roof and can be folded down backwards when not required. This reduces the overall height and silhouette of the system. Mounted on front of the turret is the fire control radar which tracks the target.