At least 30 of 64 ordered T-90S/SK main battle tanks ordered from Russia reportedly arrived in Vietnam before 2018 ended.
“The first batch of T-90S MBTs – totalling no fewer than 30 platforms – was delivered to a Vietnamese seaport in December ,” according to a source of Jane’s.
In July 2017, Russian news agency TASS reported that Russia’s Uralvagonzavod (UVZ) will supply 64 T-90S/SK to Vietnam.
According to TASS, the T-90S features powerful weaponry, modern fire control system, combined steel and composite armor and high maneuverability, capable of fighting in all weather. The T-90SK is designed to provide unit control and communication with command posts and to act in unit formations.
Sources: https://www.janes.com/article/85463/first-t-90s-mbts-arrive-in-vietnam; http://tass.com/trade-cooperation/954768