The R-29RM Shtil was a liquid propellant, submarine-launched ballistic missile in use by the Russian Navy. It had the alternate Russian designations RSM-54 and GRAU index 3M27. It was designed to be launched from the Delta IV submarine, each of which is capable of carrying 16 missiles. The R-29RM could carry four 100 kiloton warheads and had a range of about 8,500 kilometres (5,300 mi). They were replaced with the newer R-29RMU2 Sineva and later with the enhanced variant R-29RMU2.1 Layner.

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.