The Stealth ultra-high-efficiency dual-flush toilet from Niagara is equipped with two flush options: 0.5 gal. per flush (half) and 0.95 gpf (full), with an average of 0.65 gpf. It includes a low-friction ceramic surface and fully glazed 2” trapway. When the half flush button is depressed, the Stealth’s vacuum-assist power chamber is sealed off to form a suction that prevents the water inside from being included in the flush. The suction force then pulls the wastewater into the trapway and as water empties from the tank, the trapway is filled completely.