1x BetaFPV SPI 2.4GHz Micro Receiver - FrSky. Specification ofF4 1S AIO FC /w SPI 2.4GHz Micro Receiver - FrSky D8. Receiver: Support External Receiver, SPI Receiver,including Frsky XM/XM+ receiver, Futaba receiver, Crossfire receiver, and DSMX receiver.