Perfect for tight spaces and small, lightweight aircraft, the TM1100 fly-by telemetry module transmits important flight information to aircraft telemetry compatible transmitters. The TM1100 module can provide important flight log information such as RF link performance and receiver battery pack voltage. It can also provide flight pack information, which could include the flight pack battery for electric-powered aircraft, or ignition batteries in gas engine-powered aircraft. When paired with an rpm sensor (available separately), the TM1100 telemetry module can provide rpm as well as temperature information.
Understanding Spektrum Telemetry Tutorials