ES900RX: MCU:ESP8285 VCC input: 5v Operation current: ~100Ma Rx To protocol: CRSF RF Frequency: 915MHZ Dimension: 12mm x 12mm x 3mm Weight: 0.60 (exclude antenna) Antenna connector: IPEX1 Telemetry output Power: Less than 17dBm Bind procedure: Supply power to the ES900RX, wait until the red LED on the ES900RX are off, immediately turn off the power, and then repeat again the above steps. When the ES900RX is powered on for the third time, the red LED light will start to double flash quickly, which means that the ES900RX enters the binding mode module to Radio transmitter, and choose External RF mode to CRSF protocol, then you can find ELRS menu from the Radio , Enter into ELRS and press [Bind], the Red LED on the ES900RX module will turning off then start blinking slowly and finally to be solid , this means bind successfully. ES900RX firmware update by wifi procedure: Make the ES900RX enter into Bind mode and then wait around 1 minute and 't bind with it , then the ES900RX would get into Wifi mode automatically, you could connected the wifi hot pot "ExpressLRS RX" by enter the password "expresslrs" Visit the firmware update website by enter "10.0.0.1" , and choose the correct firmware then click "update" , wait for around 1~2 minutes, the update progress would finished and you can find "firmware update successful and reboot" , that means update is finished. Material: plastic+metal Color: as shown Package Contents: 1 x 915MHZ ES900RX module 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.