The 1-2081205-3: It terminates with a solder center contact and a crimped shield, with a nickel-plated zinc body and a gold-plated copper alloy center contact. Rated to 18 GHz with a 335 V voltage ceiling, this jack is meant for precision RF signal paths where the cable is formed to a fixed route and the connector is not regularly disconnected.
The 50 Ohm impedance and 18 GHz frequency ceiling define the signal path capability — this jack will pass a clean signal through Ku-band without a significant impedance bump at the launch. The 500 mating cycles mean it is not a test-port connector for daily reconnection; it is a semi-permanent install where the cable is formed once and the connector stays mated.