Play any music through your car's radio from your phone, Ipod or MP3 player when Bluetooth or Aux ports are not available. Featuring 20 different transmitting frequencies, you can listen to your music regardless of your location or signal strength. The TuneTone FM transmitter is designed to work with your car stereo and is compatible with all types of stereos with FM radio receivers. Just plug in the transmitter to your device, set the channel on the TuneTone device, set your stereo FM channel to match the TuneTone and hear your music play through your car stereo. This transmitter lets you add functionality to your car's stereo system and gives you the ability to play any music as you please. Requires two AAA batteries (not included). Included On/Off switch helps conserve battery life when not in use.