The TOTO Eco Drake and Drake Elongated Toilet Bowl 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 California’s 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