Genuine OEM Audi Brake Pad Wear Sensor, part number 4S0615437B. This sensor is designed to monitor the wear level of the brake pads, providing a critical signal when replacement is necessary. Measuring approximately 15 cm in length, it ensures accurate and reliable detection. Using a genuine OEM sensor guarantees precise fitment and electrical compatibility, which is essential for the proper functioning of the vehicle's braking system warning indicators.