This product is a Genuine VW / Audi Fuel Injector Retaining Bolt with the part number WHT004923B. It is used to secure the fuel injector in place and prevent it from moving or becoming loose. This bolt is specifically designed for use in Volkswagen and Audi vehicles and is an authentic OEM part. It is made of high-quality materials to ensure durability and reliability. This fuel injector retaining bolt is an essential component in the fuel injection system and is crucial for proper engine performance.