Samsung SPH-M620ZKASPR - Manual (Page 45)

Section 2A: Phone Basics 19
Phone Basics
23. microSD Card Slot allows you to install a microSD card for
use in data and media storage. (You can either use the
microSD card included in the phone box or any other
compatible microSD card up to 2GB.)
24. FLIP Button allows you switch between the Main LCD
and the smaller Phone Display screen. This toggling
between the two screens also activates/deactivates
certain side-specific features.
25. Lock Button allows you to lock both the phone’s keypad
and Navigation Pad.