EMISORA FRSKY TANDEM X20S DUAL 900/2.4GHZ (NEGRA)

You'll be hard pressed to find another 6-channel system with as many functions as the 6K at a comparable price. Telemetry sensors monitor critical flight data, including temperature, RPM, altitude, receiver battery voltage, external voltage and variometer. It's compatible with S.Bus and S.Bus2 servos