The TOTO Aquia IV Arc 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 curved shape offers a contemporary and sleek design to complete your bathroom. Features TOTO's Dual-Max dual flush option, allowing you to proactively conserve water usage, allowing 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 Cube tank meets the standards for EPA WaterSense(R), and California's CEC and CALGreen requirements. The Aquia IV Arc includes a tank to bowl gasket, tank to bowl hardware, and toilet bolt caps. Additional items needed for installation and use must be purchased separately: toilet bowl, wax ring, toilet mounting bolts, and water supply lines.