Genuine OEM Audi Engine Timing Chain Guide Rail, part number 06M109513G. This guide rail is a critical component within the engine's timing system, responsible for precisely guiding the timing chain. Installed on the left side, it ensures the chain maintains correct tension and alignment, preventing slack and potential damage. Constructed from durable plastic and metal, it weighs approximately 0.1561 kg. Using a genuine OEM guide rail ensures the correct material composition and dimensional accuracy, which are vital for maintaining precise engine timing, reducing wear, and extending engine life.