The TOTO Eco Drake and Drake Elongated Toilet Bowl for 10 Inch Rough-in is designed for use with the following tanks: Eco Drake ST743E 1.28gpf, Eco Drake Transitional ST744E 1.28gpf, or Drake ST743S 1.6gpf. The bowl features an extra-large siphon jet, and a large trapway. When paired with the Eco Drake ST743E 1.28gpf tank, it meets the standards for EPA WaterSense, and Californias CEC and CALGreen requirements. Additional items needed for installation and use must be purchased separately: tank, wax ring, toilet mounting bolts, water supply lines, and toilet seat.