Genuine OEM Volkswagen Crankshaft Sealing Plug, part number N91119402. This plug is designed to seal an opening in the crankshaft or engine assembly, preventing oil leaks and maintaining internal pressure. It is located in the crankshaft assembly as indicated in the diagram. Genuine OEM sealing plugs are manufactured to exact tolerances to ensure a secure, vibration-resistant fit that maintains the integrity of the engine lubrication system.