Genuine OEM Audi V-Ribbed Belt Tensioner, part number 038903315AP. This component is crucial for maintaining correct tension on the V-ribbed belt, ensuring efficient power transfer to engine accessories. Constructed from durable metal, it weighs approximately 0.691 kg. Opting for a genuine OEM tensioner ensures precise spring calibration and robust construction, which are vital for preventing belt slippage and extending the life of the accessory drive system.