A small 20x20mm stack at an affordable price. The basis is a FC with an F411 processor. FC has large soldering pads for easier construction, 5V 2A BEC, OSD, connector for easy connection of DJI FPV and 16MB Blackbox. The ESCs use BlHeli_S firmware, includes a current sensor and can handle a maximum current of 40A. It is especially suitable for 3-4" copters, cinewhoops and 5" ultralights. The stack can be powered by a 3-6S Lipo battery. The mounting holes are 20x20mm M2.