Genuine OEM Volkswagen Secondary Air Pump, part number 04E959231C. This pump plays a critical role in the emissions control system by injecting fresh air into the exhaust stream, aiding in the oxidation of unburnt hydrocarbons and carbon monoxide. It is an integral component of the vehicle's exhaust gas treatment. Weighing 1.335 kg, this genuine OEM pump ensures correct air flow and pressure, which is vital for maintaining emission compliance and optimal engine operation.