With this FM transmitter, Enhance your muisc experience through your home or car stereo. Compatible with all iPods, as well as iPhone. Plug in the audio plug to your portable music player or car to play your music. It has a LCD screen to show the operation. You can avoid signal interferes by adjusting the channel setting with the two buttons. The product is power from iPod or iPhone. Work distance is up to 33 ft (in open space). The frequency is 87.6 - 107.9 Mhz, 0.1 Mhz/step.