The YF-20 is a Chinese liquid-fuel rocket engine burning N2O4 and UDMH in a gas generator cycle. It is a basic engine which when mounted in a four engine module forms the YF-21. The high altitude variation is known as the YF-22 is normally paired with the YF-23 vernier to form the YF-24 propulsion module for second stages. New versions when used individually for booster applications are called YF-25.

The Long March 2D, also known as the Chang Zheng 2D, CZ-2D, and LM-2D, is a Chinese two-stage orbital carrier rocket mainly used for launching LEO and SSO satellites. It is manufactured by the Shanghai Academy of Spaceflight Technology (SAST).