The FuMO 21 (Funkmess-Ortung, "Radio-direction finder, active ranging") was designed in 1941 as a search radar for Nazi Germany's Kriegsmarine, suitable for ships between light cruiser and large torpedo boats in size. First designated FMG[Note 1] 39G(gL),[1] it received its final designation when the Kriegsmarine revised its radar nomenclature system around 1943.[2] It was derived from the earlier Seetakt search radar and had an antenna 2 m × 4 m (6 ft 7 in × 13 ft 1 in) in size.[1]
