Genuine OEM Volkswagen Non-Return Valve, part number 03F103156A. This valve is designed to allow fluid to flow in only one direction, preventing backflow and maintaining correct pressure within the engine system. It is a small, precision-engineered component located within the engine block. Measuring approximately 0.046 meters in length, this valve is crucial for maintaining engine integrity. Genuine OEM parts ensure exact specifications and reliable performance, crucial for preventing costly damage.