https://www.continental-automotive.com/TPMS
The Tire Pressure Monitoring System (TPMS) from Continental measures the pressure inside a tire directly and transmits the information to the vehicle display or via app even to a smartphone. The driver is alerted of a critical situation by means of a corresponding signal.

The TPMS takes the reading directly on the wheel. Battery-fed sensors mounted on the rim and integrated into the valve measure the tire's inflation pressure and send a high-frequency signal with coded information to a receiver. Special software in the control device then processes the data received and shows it on a display on the instrument panel.