Abstract: A dual flush device is disclosed to provide a full flush for removing solid waste and a water-saving partial flush for removing liquid or light solid waste in a toilet. It includes a first flush handle attached to a shaft to raise a lever to open a flapper valve, and a second flush handle that overlaps the first handle and opens the flapper valve through the first handle. A float assembly is disclosed to be used either with the dual flush device or with the original single flush lever assembly to prematurely close an opened flapper valve and reduce water consumption. Using the original flapper valve in a conventional toilet tank, a dual flush function is achieved by any of the three implementation choices: (1) the dual flush device alone; (2) the dual flush device and a float assembly; and (3) a float assembly alone.