Maybe you want to know the voltage of your onboard battery(s), the RPM the motor is turning or the temperature of your ESC. In this day and age RC is not just one way communication anymore. Traditional radio systems just transmit signals to the receiver, but Telemetry-capable systems also send real-time data from your model back to your transmitter. The S.BUS2 Telemetry Link was developed based on communication protocol disclosed from Futaba for use with specific Futaba S.BUS2 radios and compatible Castle Creations ESCs. Telemetry data can be displayed on the transmitter screen, or notify you when a defined threshold is exceeded, (battery voltage, ESC temperature, etc.) you can configure a vibration or sound alert from the radio.