The RSD-10 Pioneer was an intermediate-range ballistic missile with a nuclear warhead, deployed by the Soviet Union from 1976 to 1988. It carried GRAU designation 15Ж45 (15Zh45). Its NATO reporting name was SS-20 Saber.
RT-21M Pioneer missile and launcher on display in Vinnytsia
RSD-10 missile and its transporter erector launcher
RSD-10 Pioneer missile with re-entry bodies next to a Pershing II at the US National Air and Space Museum
Intermediate-range ballistic missile
An intermediate-range ballistic missile (IRBM) is a ballistic missile with a range of 3,000–5,500 km, between a medium-range ballistic missile (MRBM) and an intercontinental ballistic missile (ICBM). Classifying ballistic missiles by range is done mostly for convenience. In principle there is very little difference between a low-performance ICBM and a high-performance IRBM, because decreasing payload mass can increase the range over the ICBM threshold. The range definition used here is used within the U.S. Missile Defense Agency.
IRBM and MRBM missiles.