Genuine OEM Audi Engine Sprocket, part number 03C115121J. This toothed wheel is a vital component within the engine, designed to engage with a drive chain or belt to transmit rotational motion and power. It is typically found in assemblies such as the oil pump drive or timing system, ensuring precise synchronization of engine components. With a diameter of approximately 74mm, this sprocket is engineered for durability and accurate engagement. Using a genuine OEM sprocket guarantees the correct tooth profile, material hardness, and dimensional accuracy, which are crucial for smooth operation, reduced wear on the chain, and the overall longevity of the engine's internal mechanisms.