Genuine OEM Audi Engine Control Chain Slide Rail, part number 05A109201A. This essential component is part of the engine's timing chain system, designed to guide and support the timing chain as it rotates. It ensures the chain maintains proper tension and alignment, which is critical for precise valve timing and the overall smooth operation of the engine. The slide rail is typically made from a durable, low-friction polymer or composite material to withstand constant contact with the moving chain. Weighing approximately 0.1 kg, it is engineered for exact fitment within the timing cover. Choosing a genuine OEM slide rail guarantees the correct material properties, precise dimensions, and durability for reliable, long-term engine performance.