FM Transmitters ~ Broadcast MP3s to Your Car's Antenna Our customizable FM Transmitters plug into an automobile's standard 12 volt "cigar recepticle"-style power outlet. Using one of many FM radio frequencies (user-selectable) the unit transmits a powerful signal to the vehicle's radio attena, allowing the user to wirelessly connect an mp3/PMP player to their auto's stereo system. Music can be sent from built-in flash storage (use included USB cord to load files) or from the user's own audio device plugged into the unit via mini-jack.