NBI LS Exhaust Port CoversTired of fighting with painters tape that wont stick to oily cylinder heads? These exhaust port covers are the perfect solution for transporting or storing your engine. Each cover comes with all necessary hardware and O rings to seal up your exhaust ports securely. The O rings provide a watertight seal, keeping dirt, moisture, and debris out of your engine. For heads that already have O rings in the exhaust ports, you can choose the flat cover option