Parrot AR Drone 2.0 Navigation board The navigation board includes the sensors and a 40 MIPS microcontroller with a fast 12 bits ADC converter. The navigation board has one ultrasonic transceiver and one ultrasonic receiver to measure the height of the drone up to 6 meters / 20 feet. This kit includes 1 navigation board and 4 screws An altimeter to adjust the altitude with greater precision