Genuine OEM Audi Engine Chain Tensioner, part number 06F109217A. This critical component is responsible for maintaining the correct tension on the engine's timing chain. By preventing slack, it ensures precise synchronization of the crankshaft and camshafts, which is vital for optimal engine performance and longevity. Constructed from durable materials, it is designed for reliable operation under engine stresses. Using a genuine OEM chain tensioner guarantees the correct spring force and damping characteristics, which are essential for preventing timing chain rattle, wear, and potential engine damage.