The Nano Dual Flush Elongated Toilet is built with Niagara’s patented Stealth Technology. The Nano is a high-power, low-maintenance, no waste toilet that guarantees a powerful, clean flush every time, the company says. The Nano is WaterSense-certified and is one of the most water-efficient toilets available, using 77% less water than most other toilets on the market, the company notes. The dual flush technology allows people to select either 0.5 or 0.8 gallons-per-flush with the same power as the industry standard 1.6 gpf. Niagara Conservation.