Ideal for Specialized Applications: Tailored for any application where extreme force and heat resistance is a must including Top Fuel, Funny Car, and Marine Engine applications.XH-432 XtremeAlloy: The hallmark of excellence in exhaust valve material construction.Built to Last: Featuring chrome stems and hard tips for exceptional longevity and wear resistance.Optimized Performance: Swirl polished under head areas and fully machined combustion faces improve airflow and combustion efficiency.