eventually, the limited frequency range of a 14 mm connector and its high manufacturing cost overcame its ease of assembly and the gr-874 was supplanted generally by the 7 mm type n connector and its variants, the bnc connector and the tnc connector, and the later higher frequency 3.5 mm sma connectors. general radio, then still a major source of rf test equipment, designed the incompatible gr-900 as a 14 mm successor to the gr-874, filling the industry's need for a higher performance sexless connector for fully reversible lab standards and related test equipment. the gr-900 was in turn succeeded in this essential niche role by the completely sexless apc-7 connector.