Genuine OEM Volkswagen Water Pump Pulley, part number 06E121031C. This ribbed pulley is a critical component that transmits power from the engine's accessory drive belt to the water pump, enabling continuous circulation of coolant. It is positioned on the water pump shaft, driving the pump impeller. Weighing 0.357 kg and measuring 0.139m x 0.139m x 0.044m, this genuine OEM pulley is manufactured to precise tolerances, ensuring smooth and efficient power transfer without excessive vibration or wear, which is vital for maintaining optimal engine operating temperatures and preventing overheating.