Genuine OEM Volkswagen Three-phase Alternator, part number 06H903017EX. This component is responsible for generating electrical power to run the vehicle's systems and recharge the battery while the engine is running. It is typically mounted to the engine block. The alternator features a pulley for belt drive and electrical connections for output and regulation. Genuine OEM alternators are precisely manufactured to deliver consistent voltage and current output, ensuring the longevity of the vehicle's electrical components and battery.