When using this FM-transmitter on a iPhone, a message might come up as "This accessory is not made to work with iPhone" * The easiest way to broadcast your music while charging your iPod MP3 player * Compact and stylish. * Transmits stereo quality sound from your portable music player to your car FM radio. * All frequency tuning allows endless selection of radio frequencies from 88.1 to 107.9 mhz with an increment of 0.1 mhz.