Genuine OEM Audi Accessory Belt Idler Pulley, part number 077109244F. This pulley is a key component in the accessory drive system, designed to guide and maintain proper tension on the accessory belt. It measures approximately 78mm in diameter and 31mm high, weighing 0.36 kg. Choosing a genuine OEM idler pulley ensures the correct bearing quality and dimensions, providing smooth operation and preventing premature wear on the accessory belt and other components.