Genuine OEM Volkswagen Multi-Ribbed Belt, part number 078903137BC. This belt, identified as item 1 in the diagram, is responsible for driving various engine accessories including the alternator, power steering pump, and air conditioning compressor. Its multi-ribbed design ensures efficient power transfer and longevity. Manufactured to precise specifications, it provides optimal tension and resistance to wear and heat. Genuine OEM belts are engineered for exact fit and performance, preventing premature failure and ensuring all accessory systems operate correctly.