Brake pad wear sensor

Rolls-Royce part number 34356779247 is a brake pad wear sensor for the Rolls-Royce Phantom. It is a small electrical device that is mounted on the inside brake pad. As the brake pad wears down, the sensor makes contact with the rotor and sends a signal to the car's computer. The computer then turns on a warning light on the dashboard to indicate that the brake pads need to be replaced.