Genuine OEM Volkswagen Clamping Washer, part number N91121601. This washer is engineered to provide spring-like tension, helping to maintain clamping force and prevent fasteners from loosening due to thermal expansion or vibration. It is a critical component for ensuring the long-term stability of door and interior trim assemblies. Using genuine OEM washers is vital for maintaining the correct preload on fasteners, preventing damage to surrounding materials and ensuring a rattle-free service life.