This product is a genuine Porsche knock sensor with the part number 0PB905377B. It is used to detect abnormal engine vibrations, or knocks, and send a signal to the engine control unit to adjust the ignition timing. This helps to prevent engine damage and improve overall performance. The sensor is designed specifically for Porsche vehicles and is made with high-quality materials for reliable and accurate detection. It is essential for maintaining the proper functioning of the engine and ensuring a smooth driving experience.