BlueSource HydroRight Dual Flush Converter HYR271 Converts standard 2-piece toilet into water-saving dual flush toilet Drop-in installation with no tools or tank removal needed Fits 1.6 to 3.5+ GPF toilets with 2 INCH flush valve Designed to fit standard flush valves up to 2 1/2 Permafit silicone seal is chemical resistant and will not warp