The R-29RMU2.1 Layner is a Russian liquid-fuelled submarine-launched ballistic missile (SLBM) and the newest member of the R-29 missile family, developed by the Makeyev Rocket Design Bureau and produced by the Krasnoyarsk Machine-Building Plant. Derived from the R-29RMU2 Sineva SLBM, the Layner can carry twelve nuclear warheads, three times as many as Sineva. It was expected to enter service with the Russian Navy's Delta IV-class submarines after a successful test programme that spanned from May to September 2011. The Russian Navy confirmed in 2014 that the system was now in use.

K-84 Ekaterinburg is a Project 667BDRM Delfin-class nuclear-powered ballistic missile submarine. The submarine was laid down on 17 February 1982 at the Russian Northern Machine-Building Enterprise (Sevmash). It was commissioned into the Soviet Navy on 30 December 1985. After the collapse of the Soviet Union, the submarine continued to serve in the Russian Navy. Initially known only by its hull number, in February 1999 it was renamed after the city of Yekaterinburg.