Genuine VW/Audi Oil Filter Cap Drain Plug O-Ring - N90405402 - This genuine OEM VW/Audi oil filter cap drain plug O-ring is designed to fit specific VW/Audi vehicles and is a direct replacement for the original part. This O-ring helps to ensure a tight seal and prevent any oil leaks. It is made to the same exacting standards as the original part and is an essential component for any oil filter change.