The FrSky Smart Port Lipo Voltage Sensor plugs into the balance port of your battery pack and allows you to monitor pack voltages while flying. No more guessing about your battery condition.
The FrSKY Battery Voltage Sensor is used with the FrSKY telemetry system. No hub is required to use this sensor. (Receiver must support external sensors.)
Another member of the redundancy bus family brings many improvements and new features. Up to 24 channels, stabilization, black box, display for basic settings.