Simply plug your USB flash drive or MP3 player (or any audio source with an audio output like a PDA or CD player) into the MP3 FM Transmitter, and then tune to the specified FM channel. You can immediately enjoy listening to your favorite digital music over your car stereo. The MP3 FM Transmitter can read MP3 files located in storage devices and wirelessly transmit music onto your car stereo with digital stereo quality. There is no need to purchase expensive MP3 car stereos or the need to keep bulky music CDs!