The TOTO Aquia® IV dual flush 1.28 and 0.9 GPF auto flush Compatible toilet tank is designed for use with the Aquia® IV dual flush bowl. The Aquia® IV tank includes a tank-to-bowl gasket, tank-to-bowl hardware, and toilet bolt caps. The Aquia® IV tank features Toto's dual-max dual flush option, allowing you to proactively conserve water usage. The chrome center-mounted push button that sits atop the tank allows you to choose between a 0.9 GPF rinse or 1.28 GPF for tougher jobs. This version of the Aquia® tank offers TOTO T40 Washlet®+ and auto flush compatibility for when you are ready to upgrade to a hands-free flush system with an electronic bidet seat. The Aquia® IV tank meets the standards for EPA WaterSense, and California's CEC and CALGreen requirements. Additional items needed for installation and use must be purchased separately: toilet bowl, wax ring, toilet mounting bolts, and water supply lines.