Audiovox GSM 900 system - Manual (Page 20)

6
Key Function
Power On/Off Key
Long press this key to turn the handset power on or off. To access
the menu functions, you can use this key to return to a previous
screen of the menu.
Send Key
Press this key to make your call or confirm menu selections.
Selection Key
This key is used to navigate and select among function items in the
menu or submenu. For example, to access the Phone Book, you can
press the key downward to enter the Phone Book item.