Samsung SCH i830 - Manual (Page 19)

Section 2: Understanding Your Phone 19
Key Functions
Section 2
13. End Key: Ends a call. Press and hold this key for a few
seconds to turns the radio On or Off. When you receive
an incoming call, press to mute the ringer and send the
call to voicemail.
14. SD Card I/O Slot: This I/O expansion slot allows you to
insert an SD memory card to add additional memory and
storage capacity.
15. Action Key: Pressing when navigating through a menu
selects the highlighted choice in the menu.
16. Status Icons: These icons indicate, current signal
strength, and the availability of many other features and
functions of your phone.