See also:

Switching the microphone to mute
When a call is active, the microphone can be muted. 1. "Telephone". 2. "Active calls". 3. "Microphone mute" A microphone that has been switched to mute is automa ...

Maintenance
The battery is maintenance-free, i.e., the electrolyte will last for the life of the battery. Your service center will be glad to advise you on questions regarding the battery. ...

Office
...