The T-90's main armament is the 2A46M 125mm smoothbore tank gun. This is a highly modified version of the Sprut anti-tank gun, and is the same gun used as the main armament on the T-80-series tanks. It can be replaced without dismantling the inner turret and is capable of firing armour-piercing fin-stabilised discarding sabot (APFSDS), high-explosive anti-tank (HEAT-FS), and high explosive fragmentation (HE-FRAG) ammunition, as well as 9M119M Refleks anti-tank guided missiles. The Refleks missile has semi-automatic laser beam-riding guidance and a tandem hollow-charge HEAT warhead. It has an effective range of 100 m to 6 km, and takes 17.5 seconds to reach maximum range. Refleks can penetrate about of steel armour and can also engage low-flying air targets such as helicopters.