Frequency matching steps: 1. After the receiver is connected to the flight control, connect USB to supply power to the flight control.After inserting USB for the first time, disconnect USB as soon as you see the LED lights on the receiver go out.Repeat the operation twice. When the USB is plugged in for the third time, the LED will start to double flash, and the receiver will enter the code checking mode. 2. After connecting the 915M ELRS tuner module and the remote controller correctly, copy the ELRS. LUA file to the SD card in the remote controller. The directory is SD Card/Scripts/tools, and then run ELRS. LUA for Bind operation. 3. After the binding is successful, the LED on the receiver will turn on normally, and the telemetry signal can also be received. The appearance, color, and printing of the product from batch to batch, but this does not affect use. Description: ESP8285 MCU(FCC) SX1276 RF Frequency range: 915MHz FCC Maximum receiving refresh rate: 500HZ Minimum receiving refresh rate: 25HZ Operating voltage: 5V Firmware: BETAFPV_900_RX 3.0.0.HEX Indicator status: Double flashing: code checking mode Slow flashing: No transmission signal is received Always on: Received transmission signal Flash: WIFI upgrade mode Material: PCB colour: Black Package Contents: 1 x Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.