In a corner cube radar reflector of the octahedral radar reflector cluster type wherein three planar radar reflecting plates are orthogonally disposed all in planes of non-coincidence to the horizon, an improved holder is disclosed. Typically first and second tapered members are conformed to the apexes of upwardly and downwardly opposed corner cubes with the upper cube in the "catch rain" position. The tapered members are urged one towards another and fastened to a vertical support, which support can either be rigid or alternatively tensive. There results a support for the reflector in which the designed corner cubes are addressed with optimum solid angle disposed to the horizon from which radar interrogation will most probably occur.