There are also transmitters that let you choose from different preset frequencies while others don’t let you change broadcast frequency. This can be a big problem in the long run.
Input options that come with the device is another thing you should check. Many transmitters have a standard audio jack that could be connected directly to the headphone output or line of an MP3 player.
However, you might also want to look for transmitters that include SD card slots, USB connections, as well as other options. There are also transmitters that play music from an SD card or USB stick with no need for a different MP3 player.
Check the Extremes
Upon removing the FM transmitter for car out of its package, first, you should tune this and your head unit to similar frequency. When the transmitter lets you select an FM frequency, you will want to start by checking the FM dial’s extremes.