It is fitted with a fume extractor and thermal sleeve but has no muzzle reference system. The 120 mm smoothbore gun is 6 m long and weighs 2,600 kg complete with breech mechanism. Some years ago China did develop and place in production the 120 mm self-propelled anti-tank gun Type 89 (details of which are given in the Tank destroyers section) which has a similar 120 mm smoothbore gun and the 120 mm weapon for the Type 59 upgrade is probably identical. The 120 mm smooth bore is fitted to the Type 90, Type 85-IIM and Type 85-III MBTs and has enabled the crew to be reduced to three, commander, gunner and driver. The exact origin of the Chinese 120 mm smoothbore is not known as in the past, with the exception of the Western 105 mm rifled tank gun, all Chinese tank guns have been of Eastern design. This has also been referred to in Chinese sources as the Type 59 Kai.

As of early 1999 there are no known orders for the NORINCO 120 mm T-54/Type 59 MBT upgrade. China North Industries Corporation (NORINCO) has developed an upgrade package for the widely deployed Chinese Type 59 and Russian T-54/T-55 MBT that includes the replacement of the current 100 mm rifled tank gun by a 120 mm smoothbore gun.

Military tank types