Too difficult to access the USB port on your compact 2-4" quad? Say goodbye It's time to say goodbye to this trouble With this Bluetooth stack, you don't need to connect your quad to the PC for FC and even ESC tuning, everything can be done wirelessly in the SpeedyBee app. Tune Flight controller and ESC wirelessly Power the quad, connect the SpeedyBee app via Bluetooth, configure the UART Ports,PID,OSD and every other settings on this flight controller Also, every parameter of the BLHeli_S ESC in this stack can be set via the app. Change motor directions wirelessly With this stack, when you finish your build, connect to the SpeedyBee app, change the motor directions just in a few simple steps. Then take off.