The sixth SSK is named Ba Ria-Vung Tau (hull number HQ-187), it was launched in September 2015. To date, the Vietnamese Navy has operated the five submarines in the class - the Hanoi, Ho Chi Minh, Haiphong, Khanh Hoa and Da Nang. The government of the Socialist Republic of Vietnam ordered from Russia’s official arms exporter Rosoboronexport six Project 636.1 diesel-electric submarines worth about $2 billion in late 2009. Vietnam has been receiving standard-issue submarines outfitted with the Club-S (export designation of the Kalibr system; SS-N-27 Sizzler) cruise missile system.