Genuine OEM Volkswagen hexagon socket head bolt, part number N91187301. This fastener is engineered for the secure attachment of critical engine components, including the high-pressure fuel pump assembly. It is located at position 11 in the assembly diagram. This bolt features a precise hexagonal socket drive and a durable cylindrical head. Genuine OEM hardware is essential for maintaining the correct clamping force and vibration resistance required for high-pressure engine systems.