Skystars F405 HD is a control unit with an F4 processor. It uses a gyro BMI270, has 8MB of memory for blackbox and 5V / 3A and 10V / 2A BEC. The unit also has a connector for connecting DJI FPV and OSD, so it can be conveniently used on helicopters with digital or analog video transmission. The pads for connecting LEDs in the corners of the unit are also nice.