The T-90  is a third-generation Russian main battle tank that entered service in 1993. The tank is a modern variation of the T-72B and incorporates many features found on the T-80U. Originally called the T-72BU, but later renamed to T-90, it is an advanced tank in service with Russian Ground Forces and the Naval Infantry. The T-90 uses a 125 mm 2A46 smoothbore main gun, the 1A45T fire-control system, an upgraded engine, and gunner's thermal sight. Standard protective measures include a blend of steel and composite armour, smoke grenade dischargers, Kontakt-5 explosive-reactive armour and the Shtora infrared ATGM jamming system. It was designed and built by Uralvagonzavod, in Nizhny Tagil, Russia.