Genuine OEM Audi V-Poly Belt Tensioner, part number 06M903315L. This critical engine component is designed to maintain the proper tension on the accessory drive belt, ensuring efficient power transfer to components like the alternator, power steering pump, and air conditioning compressor. It prevents belt slippage and excessive wear, contributing to the longevity of the belt and connected accessories. Weighing approximately 0.657 kg, this tensioner is engineered for precise fitment and durability. Choosing a genuine OEM belt tensioner guarantees factory-specified tensioning force and robust construction, crucial for preventing premature belt failure and ensuring quiet, reliable engine operation.