Genuine OEM Volkswagen Engine Valve Spring, part number 030109623J. This precision-engineered spring is a critical component within the engine's cylinder head, responsible for closing the intake and exhaust valves after they have been opened by the camshaft. It ensures proper valve seating and prevents valve float at high RPMs. Weighing 0.032 kg and measuring 0.042 meters in length, this spring is designed for specific tension and fatigue resistance. Choosing genuine OEM ensures the correct spring rate, material composition, and heat treatment for optimal engine performance and longevity.