Zte Grand S Flex User Manual page 134

A count-down clock appears above the frequency and the radio
is turned off when the clock counts down to 0:00.
To turn off FM radio immediately:
Touch at the top left of the screen.
To set your radio region:
FM radio frequency ranges differ in different regions.
Touch the Menu Key > World region to select the region you
are in.
NOTE: If you change the region setting, previously saved
favorite channels are not shown until you switch back to the
original region setting.
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