Jabra GN1200 Smart Cord fits virtually all telephones featuring a standard RJ9 modular connector and works with any GN/Jabra headset equipped with Quick Disconnect The GN 1200 Smart Cord features eight separate wire schemes - including three with built-in microphone amplification. Simply connect your headset to the GN 1200 Smart Cord quick disconnect and slide the switch, located under the panel on the side of unit, until you have a dial tone. It's as simple as that. Compatability type is selectable through dial on cord.