See also:

Volume control buttons
Models without Hands-free system Models with Hands-free system Press the “+” button to increase the volume. Press the “−” button to reduce the volume. A number indicating the volume ...

Center ventilators
Center ventilators Move the tab to adjust the flow direction. ...

Models with Hands-free system
Press this button for more than 1.5 seconds if you wish to immediately cut the volume to zero. The audio display will show “MUTE”. If you press the button for more than 1.5 seconds again, the origin ...