It's a panel-mount bulkhead connector — front-side nut secures it to the panel, and the bayonet lock gives a quick quarter-turn mate with the matching BNC plug. The 500 V voltage rating and 0.15 dB insertion loss suit it for video distribution, broadcast, and test equipment signal paths where 75 Ohm impedance is standard. This is a complete bulkhead install kit: the package includes the connector body, one contact, one ferrule, one gasket, one lockwasher, and one nut — six pieces total.
Termination is crimp for both the centre contact and the shield. The cable group specified is Belden 8218 — a 75 Ohm coaxial cable commonly used in CCTV and broadcast runs. The shield termination crimp ferrule is included in the kit, so you have everything to terminate one cable end in a single order line.