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 electronic bidet seat. The Aquia IV tank meets the standards for EPA WaterSense(R), 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.