It's your best choice for small plane or coptors, such as fox or T80 and T380.
FrSky D4R-II 4ch 2.4Ghz ACCST Receiver (w/telemetry)
• Lighter weight and physically smaller than D8R-II & D6FR
• Integrated warning alarm for low voltage, poor reception, etc.
• One external analog telemetry port and one digital data-stream port (Connects to FrSky Sensor Hub FSH-01).