Precise details: RadioMaster R81 2.4GHz 8CH Over 1KM SBUS Nano Receiver Compatible FrSky D8 Support Return RSSI for RC Drone Description: Brand Name: RadioMaster Item Name: R81 Nano Receiver Model: R81 Weight: 2g Size: 17*11 mm Channels: 8CH Frequency range: 2400-2483.5Mhz Power input range: 4.5-6V Signal format: FrSky D8 Compatible Output format: SBUS Support return: support return RSSI Control distance: more than 1km Antenna length: Approximaltly 6cm Bind method: 1. Press and hold the BIND button on the receiver then connect power. After approximately 3 seconds, the receiver LED will be RED, the receiver is now in bind mode 2. Select the D8 protocol for the multi-protocol menu of your remote control, and press the [BIND] option, the red light of the receiver will flash indicating successful bind 3. Exit bind mode on your remote control and disconnect power to the receiver then power the receiver once more. The LED will now be solid RED indicated the bind is now done. If not please repeat step 1 and 2 Fail-safe Protection: 1. Press the BIND button once within 10 seconds of th eceiver being powered on, and the receiver will save all the current channel values of the remote control as the fail-safe value 2. 10 seconds after the receiver is powered on, the BIND button function will be disabled to prevent accidental changes to to the fail-safe settings while preparing the model for flight RSSI output: This receiver has a total of 9 channels. 8 channels + an RSSI output channel. Channels 1-8 are controlled by the remote controller, the 9th channel is the signal strength RSSI value output by the receiver itself, which can be read by the flight controller and sent to the OSD device Show signal strength. Package Included: 1 x R81 Nano Receiver