Happymodel Crazybee F4 V3.1 2-4S 4in1 12A AIO Flight Controller - SPI FrskyThe Crazybee F4 V3. 1 Flight Controller comes pre soldered with a Frsky SPI receiver and XT30 power wires. This flight controller is the default FC for TheFPFlea and the Happymodel Cine8 85mm Brushless CineWhoop, but great for other ultra light micro drones that need space and weight savings. Build your micro drone with this AIO flight controller and solve three things at once! Just add a VTX like the Happymodel Diamond VTX and your stack is good to