Using the MBU 400
Handset Main Menu
To display the Main Menu on the handset, press the OK button in the center of the navigation keys as shown below.
Main Menu Button (also OK button)
Navigation Keys 
The Main Menu displays. The following illustration describes the icons on the Main Menu screen.
Main Menu
Settings
Contacts
Intercom
Call Log Contacts 
Messages (voicemail)
The Handset Main Menu has 5 options you can select to customize and operate the phone.
Intercom - Allows you use the Intercom to communicate between two handsets registered to the same MBU. For more information, see the MBU 400 User Guide.
Messages - Allows you to access and play your voicemail messages. Your voicemail service can be provided by your Service Provider or a local mail server. If using a Service Provider for voicemail, contact that provider for more information on how to use your voicemail service. For more information, see the MBU 400 User Guide.