Product Details: Ensure your semi is Ready for the Road Ahead™ with optimal hydraulic fluid performance, with the Donaldson Duramax® Head Assembly. Due to its robust design, this replacement head assembly is able to efficiently direct hydraulic fluid while tolerating intense pressures. Engineered with a sturdy metallic body to endure the rigors of daily use and extreme pressures. FleetPride is your First Click in Heavy Duty®.