Genuine OEM Audi Chain Tensioner, part number 059109217C. This vital engine component is responsible for maintaining the correct tension on the engine's timing chain, ensuring precise valve timing and smooth engine operation. It is specifically designed for the left side of the engine. Weighing 0.331 kg and measuring 0.16 m in length, this tensioner is built to exact factory specifications. Using a genuine OEM chain tensioner guarantees optimal spring force, wear resistance, and hydraulic damping for reliable engine performance and longevity.