Genuine OEM Audi Alternator Poly-V-Belt, part number 03L903137D. This essential component is responsible for driving the alternator and various other engine accessories, ensuring their proper function. It is a multi-ribbed belt made from durable rubber, measuring approximately 1.079 meters in length. Using a genuine OEM poly-V-belt guarantees the correct material composition, rib profile, and tensioning characteristics, which are critical for long service life and preventing premature wear or failure of driven components.