[ Serial Protocol ]ELRS uses the serial protocol ( CRSF protocol) to communicate between the receiver and the flight controller board. So make sure your flight controller board supports the CRSF serial protocol. How to set up the CRSF protocol can be viewed on the fourth page of the manual. [Nano Receiver/Compact Design]the volume is 12mm x 19mm which is very suitable for Tiny whoop because of the ultra light and Nano size. [Configuration & Bind] Nano receiver could enter binding status by power on/off three times. Step: and unplug nano receiver three times; Make sure the LED is doing a quick double blink, which indicates the receiver is in bind mode; Make sure the RF TX module or radio transmitter enter binding status, which sends out a binding pulse; If the receiver has a solid light, it's bound. Name: ELRS 2.4g receiver Telemetry power: 20dbm Frequency band: 2.4g Input voltage: 5V Antenna connector: IPEX Size: 10.5x17mm Colour:Photo Color Material:plastic+metal Package Contents: 1X 2.4G transmitter With antenna 1X Connecting line 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.