Genuine OEM Volkswagen Socket Head Collared Bolt, part number N91026403. This bolt is specifically designed to secure the input shaft within a 6-speed manual gearbox. It is indicated as item 11 in the diagram, which shows a gearbox input shaft and related components. The socket head collared design ensures a secure fit and proper torque application. Genuine OEM bolts are critical for the precise tolerances required in transmission components, ensuring smooth operation and durability.