Genuine OEM Audi Upper Timing Chain Tensioner, part number 06E109217AJ. This critical engine component is responsible for maintaining the correct tension on the upper timing chain, ensuring precise valve timing and smooth engine operation. Made from durable metal with a specialized low-friction shoe, it prevents chain slack and reduces wear. Weighing 0.542 kg, its factory-specified tension and robust construction are essential for the longevity and reliable performance of the engine's valvetrain.