1.Built-in USB interface,can play the audio in your U disk. 2.Simultaneously charges your ipod using your car's DC power source (cigarette outlet). 3.Transmits ipod tunes through four available FM Radio frequency. 4.Excellent PLL wireless technology enhance noise reduction and stereo separation. 5.Precise and attractive appearance that makes you have an extra experience in using it. 6.red LED indicate the current channel you set, also it make the unit more beautiful and convenient