Genuine OEM Audi Brake Pad Wear Sensor, part number 4H0615121H. This sensor is designed to detect the wear level of the brake pads, providing a crucial signal when replacement is due. It is installed in the rear wheel assembly. With a length of approximately 31.4 cm, it ensures accurate and reliable wear detection. Choosing a genuine OEM sensor guarantees precise fitment, electrical integrity, and long-term reliability, which are vital for the vehicle's braking system.