The S-400 TRIUMF (NATO codename SA-21 Growler) is an antiaircraft and anti-missile system, which is capable of intercepting all types of modern air weaponry, including fifthgeneration warplanes, as well as ballistic and cruise missiles at a maximum range of nearly 250 miles. India is procuring the S 400 TRIUMF from Russia as part of its overall air defence effort. The system is designed to counter a variety of threats from hypersonic cruise missiles, to UAVs, airborne early warning aircraft, stealth fighters and even precision guided munitions.
The first five units are to be bought at an expected cost of USD 6.1 billion, making this the most expensive air defence system ever bought by India. Deliveries are however not expected within the next four years due to Russian commitments for their own forces and also due to an earlier Chinese order for six systems. The S 400 is a unique system that tracks targets using a mobile phased array radar. It incorporates four types of missiles that are carried on mobile launchers, which can engage targets at 120 km, 200 km, 250 km and 380 km.