See also:

Toggling Between Calls
If two calls are in progress (one active and one on hold), press the button until you hear a single beep, indicating that the active and hold status of the two calls have switched. Only one c ...

Electronic Volume Control
The electronic volume control turns continuously (360 degrees) in either direction without stopping. Turning the ON/VOLUME control knob to the right increases the volume and to the left decreases ...

Place/Retrieve a Call From Hold
To put a call on hold, press the button until you hear a single beep. This indicates that the call is on hold. To bring the call back from hold, press and hold the button until you hear a singl ...