Monitor your model's battery voltage with this Spektrum telemetry sensor designed for compatible aircraft systems. The 20-inch external voltage sensor connects to the flight pack and provides battery voltage information through a compatible telemetry system. It can be used with electric-powered aircraft or with ignition batteries in gas engine-powered aircraft. A TM1000 telemetry module and telemetry-capable transmitter are required for operation. It is also listed as an optional accessory for several Spektrum surface transmitters and radio systems.