This is a returned M540 that includes a pre-installed R-XSR receiver. This quad was returned by a customer and has not been fully tested other than testing the motors in betalight (which all work) and the FPV feed is working. However is is likely that the quadcopters needs to be configured in Betaflight.
It is sold as is as a used/faulty item and we will not offer any extra support. So if you are happy to troubleshoot and repair this quadcopter yourself you can save yourself abit of money over a new one.