Crazepony RD40 5.8GHz 40CH Diversity Receiver Audio Video Wireless for FPV Quadcopter Dimension: 80 * 65 * 15mm, Weight: 100g Frenquency control and LED display When power on,press FR, RX1 and RX2 frenquency Change, and shows on 40 channels, 5 frequency band wireless receiving Two buttons for channel and band exchange individually Wide dynamic power supply ( 7-24v).