Genuine OEM Audi Cylinder Head Cover Seal, part number 07D109091. This small but vital seal is designed to prevent oil leaks from the cylinder head cover, often around spark plug tubes or other openings. Its function is to maintain a tight barrier against oil seepage, which can lead to engine contamination and reduced oil levels. Made from durable, oil-resistant rubber, it measures approximately 0.037 meters in diameter. Choosing a genuine OEM seal ensures the correct material and precise dimensions for a reliable, long-lasting seal, crucial for engine integrity and preventing costly oil leaks.