The Zurn P6000-ECR-FF-RK 4.5 gpf Closet Aquaflush Diaphragm Kit Rebuild Kit is a replacement kit specifically designed for Zurn brand toilets. The kit includes a diaphragm with a size of 4.5 gallons per flush, making it suitable for use in commercial or industrial settings. With free express shipping in the United States, this product offers a convenient and cost-effective solution for maintaining and repairing plumbing systems.