Car MP3 Built-in FLASH 64MB/128MB/256MB/512MB/1GB Built-in FM transmitter Read MP3 file from the USB flash directly and broadcast through the FM tuner LINE-IN function 7 preset channels within 87.7-88.9 7 green LEDs that indicate 7 preset channels Car cigar socket power supply(12V DC power) 1 red LED which indicates work state(play or pause)