FrSky long range R9M and R9MM combo works in the frequency of 900MHz. The R9M module offers 4 switchable RF power outputs to so you can choose the appropriate power for different flight situations. Compared to another FrSky 2.4GHz long range receiver like the L9R, the R9 receiver has a longer operating range up to 10KM and above. Moreover, the R9 is also a redundancy receiver which can connect to another receiver to ensure the security of your aircraft.
The FrSky R9 MM is the latest 900MHz mini receiver in the long-range series. It has super low latency, high precision performance in an extremely compact design. A new feature incorporating an inverted S.Port output makes it compatible with more devices.

Specifications of R9M Module:
Item Brane: Frsky
Compatibility : R9 series
Vin Voltage Range:4V-12.6V
External Power Supply: 4V~12V (2s Li-Battery is recommended )
(*3s Li-Battery is not recommended as external power supply, or it will damage)
Telemetry Interface: Smart Port
Upgrade Interface: Smart Port
Modulations: PXX or CPPM (auto-detected)

Specifications of R9MM Receiver:
Item Brand: Frsky
Dimension: 16*10*2.8mm
Weight: 1.1g (including antenna)
Number of Channels:
Non-EU Version: 4/16CH (Telemetry)
Operating Voltage Range: DC 3.5V – 10V
Operating Current: 100mA@5V
Operating Range: Up to 10km or above
Compatibility: R9M and R9M Lite

Package Included:
Frsky R9M Module x 1
Frsky R9MM long range receiver x 1
Antenna for R9MM x 1