The KOHLER Highline toilet tank features innovative Revolution 360 technology, an advanced flushing system that uses a powerful swirling motion to thoroughly rinse the bowl. This water-efficient toilet tank also utilizes innovative AquaPiston technology, a patented flush engine that delivers a fast, powerful, and virtually plug-free flush. A 1.0-gallon flush reduces water use by more than 35% over 1.6-gallon toilets, offering a water savings of more than 4,500 gallons of water per toilet, per year. Pair this 1.0 gpf toilet tank with a coordinated Highline bowl for a complete toilet.