1)216 channels frequency can be optical at random 2) can input and transmit signals from outside audio sources such as Mp3/CD 3) No need to change any structure of car 4)3 in 1 function: multifunction charge u-disk car mp3 5)Red LED display frequency and NO.songs 6)Play Mp3,WMA,WMV etc.music formats 7) Digital switch with one key control function 8)Large built-in flash memory 9)Infrared remote control.