Ultra low flush. Widely used description of 1.6 gpf or less toilets.
Ultra Low Frequency. Frequency band in the range of 300 Hz - 3 kHz, corresponding to wavelength from 1000 km to 100 km. This band overlaps audio frequencies. Because of its very long wavelength, there is no antenna and transmitter operating at this band.
Ultra Low Flush . Designation for modern, water saving toilets. Toilets using 1.6 gallons per flush, or less.