Pocket-size, lightweight and wireless for portable, hassle-free use while on the move. Simply plug the fm transmitter into select device dock connection, device will ask to get into airplane mode, you do not need to choose it, match the frequency on the fm transmitter's LCD display with an idle frequency on your car / home stereo and start playing your tunes on your select device. This unit is compatible with the iphone, iphone 3G, iTouch I/II generation.