The MiG-21 M scries was (he first of the multi-role Fishbeds and featured a twin barrel Nudelman-Richtcr GSh-23L 23мм cannon semi-reccsscd in the underside of the fuselage, forward of the center line pylon. The MiG-21 M was powered by the R-l 1F-2S*300 engine, while the Mi(i-21SM and MiG-2IMI; variants were upgraded with a 14,550 Ibst Tumanskii R-13-300 power plant. Reconnaissance variants (MiG-21R and MiG-21 Rl) deleted the GSh-23L cannon, replacing it with a camera/FLINT pod carried on the centerline pylon. The aircraft also had Radar Warning Receiver (RWR) antennas on the wingtips.