The TOTO T40 Aquia IV WASHLET Elongated Skirted Toilet Bowl is designed for use with the Aquia IV tank. The Skirted Design conceals the trapway, which enhances the elegant look of the toilet and adds an additional level of sophistication. Skirted Design toilets also minimize the need to reach behind the bowl to clean the nooks and crannies of the exterior trapway. When paired with its tank, the Aquia IV features TOTOs DYNAMAX TORNADO FLUSH, utilizing a 360 degree cleaning power to reach every part of the bowl. The enhanced design of the Aquia IV inner bowl reduces water flow resistance and turbulence, resulting in a quieter flush. The Aquia IV bowl offers TOTO T40 WASHLET compatibility for when you are ready to upgrade. The T40 WASHLET toilet features a channel on the bowl surface to help conceal your WASHLET supply line and power cord for seamless integration. Compatible with T40 WASHLET electronic bidet seat models only. When paired with its tank, the Aquia IV meets the standards for EPA WaterSense, and Californias CEC and CALGreen requirements. The Aquia IV comes ready for install into a 12'' rough-in, but may be adapted for a 10'' or 14'' rough-in with the purchase of a separately sold adapter. Additional items needed for installation and use must be purchased separately: compatibletank, wax ring, toilet mounting bolts, water supply lines, and WASHLET or seat designed for WASHLET.