Castle Creations Spektrum X-Bus Telemetry LinkKey Features Telemetry data can be displayed on the transmitter screen, or for parameters where users only want to be notified when a defined threshold is exceeded, (battery voltage, ESC temperature, etc.), a configured vibration or sound alert from the radio can be utilized. There is no requirement for additional Telemetry Sensors to be purchased when using the Castle Telemetry Link. There are up to 7 specific data points available (varies with ESC)