Black Box Explains...Quick disconnnects..
A quick disconnect enables you to disconnect your headset without disconnecting your call or taking off your headset. This option is expecially convenient when you need to leave your desk and keep your caller on the line. When you return to your desk, all you need to do is reconnect the plug and you’re talking again. The quick disconnect works well for call centers and busy offices where files aren’t at your desk or when you need to speak to a supervisor.