Comes with ACCST 2.1 - will work with all the newer (2019/ACCESS) radios and older radios that have the internal XJT module flashed with ACCST 2.1
If you have an older radio or multiprotocol radio, the receiver needs to be flashed to 1.x
FrSky ultra mini receiver R-XSR is the evolution of FrSky full range receiver.
See our video on flashing - it's the XSR but the procedure is the same and the R-XSR comes with a cable that you can use.
Pay careful attention to the wiring order, which depends on the radio you're using to flash - order is correct for the Q X7 but NOT for the Taranis X9D+
Link to manual here