Ensure optimal engine performance with the 5263672 Expansion Plug, designed for seamless compatibility with Cummins B3.3, 4B3.9, 6B5.9, B4.5, ISB, QSB, B6.7, F4.5, C8.3, NH, NT855, N14, ISL, and ISF engines. Reliable, durable fit for professional applications.