A:Answer Actually, it is a personal transmitter. A personal FM transmitter is a low-power FM radio transmitter that broadcasts a signal from a portable audio device (such as an MP3 player, smartphone, laptop, etc.) to a standard FM radio. The transmitter plugs into the device's headphone jack and then broadcasts the signal over an FM broadcast band frequency (selected on the device), so that it can be picked up by any nearby radio. Being low-powered, most transmitters typically have a short range of 100–300 feet, which is more than enough for your car radio.
So, the device it the FM transmitter and your car radio is the FM receiver.
