It terminates to the board through a right-angle solder tail while the bulkhead flange mounts through the panel with the included lockwasher and nut. The centre contact is gold-plated phosphor bronze, good for 500 mating cycles before the plating wear starts to shift the contact resistance.
Mates with any standard BNC plug having a bayonet coupling and 50 Ohm interface — no proprietary keying. Dielectric is polyethylene, body is nickel-plated zinc alloy.
The 500-cycle rating comes from the gold-over-phosphor-bronze centre contact — that's a solid reconnect life for test-equipment or field-swap duty, but the connector was never designed for daily remating over years. The 4 GHz ceiling and 500 V rating cover most lab and instrumentation RF paths; above 4 GHz the return loss climbs past what a standard BNC interface holds.