The McCormick 378289X1 is a genuine OEM piston oil control ring designed for various International Harvester and McCormick tractor models. This essential engine component ensures proper oil lubrication and prevents oil from entering the combustion chamber. It features a bore of 79.375 mm and a thickness of 2.3622 mm, weighing approximately 0.02268 kg. This ring is crucial for maintaining engine performance and efficiency in compatible machinery.