The 031-325: It comes as a 3-piece kit: the connector body, a crimp contact, and a ferrule, all in a single bulk package. The nickel-plated brass body and gold-plated brass center contact handle the RF path, while the PTFE dielectric keeps insertion loss to 0.2 dB across the band.
This plug is specced for the AT&T 735, 735A, and Belden 735A1 cable group.
RF Performance and Operating Range
Rated 50 Ohm impedance with a 4 GHz maximum frequency and 0.2 dB insertion loss, this is a solid performer for standard BNC duty — test equipment, instrumentation, and low-power RF signal paths. Every amp through the contact makes heat, but at these signal levels the derating is academic.