The TE Connectivity 282123-75 is a 1.0/2.3 interface jack — a 75 Ohm coaxial connector built for the European-standard small-form-factor RF interconnect used in broadcast video, telecom base stations, and test equipment. This is the female socket (jack) end, designed to mate with the matching 1.0/2.3 plug. The 75 Ohm impedance and 4 GHz maximum frequency tell you it is a 75-Ohm-system part, not a 50-Ohm one — a common gotcha for anyone reaching for a generic SMA or BNC substitute.
Mounting is bulkhead — front-side nut — with a through-hole right-angle solder tail for the centre contact and shield. The shield terminates by soldering directly to the board ground plane, which keeps the RF return path short.