Genuine OEM Audi Control Chain Guide Rail, part number 03F109469C. This component is crucial for guiding the engine's timing chain, maintaining its correct tension and alignment for precise valve timing. Located within the engine's timing cover, it is made from durable, low-friction plastic. Measuring approximately 0.322m in length, using a genuine OEM guide rail ensures optimal chain operation, reduces wear, and prevents costly engine damage due to timing issues.