The Zurn P6000-EUR-EWS-RK Aquaflush Chemical and Clog-Resistant Rebuild Kit 0.5 Gallons (for Urinals) is constructed of chemical-resistant TPE material that resists chemical infiltration, which cuts short the life of black diaphragms. It is designed to fit Zurn AquaFlush, Sloan Royal, and Sloan Regal flush valves.