This KOHLER Wellworth dual-flush 1.1 or 1.6 gpf toilet tank combines water savings with powerful flush performance. An innovative two-tone flush lever offers the choice of 1.1 or 1.6 gallons per flush; the dual-flush lever is located on the side of the tank like a traditional toilet, leaving the top free for storage. The high-efficiency 1.1-gallon flush reduces water use by more than 30% over the 1.6-gallon mode, which adds up to potential water savings of more than 4,000 gallons per toilet, per year.