Jmt 1 Piece RCD 3060 Os Mini OSD FPV Module It can check two voltages and overlap them onto the video signal. Factory calibration, its precision reaches +/- 0.1V The background is light dark when the data is displaying in overlapping way, this can ensure customers read clearly and precisely under strong light environment or the light dark background 40 position data modes are for choice. (We can change the mode numbers and the displaying position according to the request of our customer)