Several mid-2000’s German vehicles (Audi, BMW, Mercedes, Porsche, Volkswagen) and some early-model Jaguar/Land Rover vehicles came equipped with LF-learning TPMS systems. Low-frequency initiators in each wheel well triggered the sensors in a certain way, so that the cars/trucks could automatically learn new IDs.
The Sens.it RS+ sensor is equipped with a large LF coil, so that it can hear the signals from the LF initiators. The large gap between the wheels and vehicle-mounted LF antennas necessitates a bigger coil, larger than is required for testing via TPMS tools.