If you are installing any of the JR style transmitter modules into your X9E these antenna leads can help you to make a nice, clean installation of the antenna. The gold threaded coax connector fits into a pre machined hole in the top of the 9XE and is held into place with the included nut and lock washer. You can then simply thread on your 2db antenna.
10/27/17 Note for customers with older X9E radios. FrSky no longer offers this lead in SMA. If you replace this lead on an older X9E you will need to get a new antenna that is RP-SMA as well.