RF series are series of Mobile Weapon used by Mars Zeon in events of Mobile Suit Gundam F90 and Mobile Suit Gundam F91: Formula Wars 0122. RF series are notable for their appearance which greatly resemble the old mobile weapons used by Principality of Zeon in One Year War era, the trait that give Mars Zeon's new name as Old Mobile Army. Their appearance is merely to put fault sense of security to Earth Federation's pilot, the internal of RF series is actually advance model of mobile weapons, possibly based on the AMS-119 Geara Doga used by Neo Zeon. Against Earth Federation's mainstray MS, the RGM-89 Jegan, the RF series are like unstopable monsters. Although smaller MS like F71 G-Cannon and RGM-109 Heavygun proved to be quite effective against these large enemies.