Genuine OEM Volkswagen Socket Head Bolt, part number N91208501. This fastener is specifically designed for securing cooling system components, such as radiator fan shrouds and housings. It features an internal drive for use in tight spaces where external hex tools may not fit. Using genuine VAG hardware ensures the bolt is made from materials resistant to the thermal cycling and moisture common in the engine bay, preventing seizing and ensuring a secure, vibration-resistant fit for the cooling fan assembly.