3678606 O-ring seal is a direct OEM replacement for Cummins ISX, QSX and X15 engines. Adopting premium fluororubber material, it resists high temperature, pressure, oil and aging. It forms tight sealing in assembly grooves to stop liquid and gas leakage. Precision molding ensures perfect fit without trimming. Reliable sealing performance extends engine service life, widely used in heavy trucks, engineering machinery and marine Cummins engine daily maintenance.