Genuine OEM Audi Belt Tensioner, part number 06E903133Q. This critical component is responsible for maintaining the correct tension on the engine's accessory drive belt, ensuring consistent power delivery to components like the alternator, power steering pump, and air conditioning compressor. It prevents belt slippage and excessive wear. Weighing 0.948 kg, this tensioner is built for durability. Choosing a genuine OEM belt tensioner guarantees factory tolerances and robust construction, providing a vibration-free service life and preventing premature belt or accessory failure.