Farm Innovators 3 gal. Plastic Heated Poultry Fountain HPF-100
Product Review (submitted on November 17, 2013):
Has kept water unfrozen down to 15 degrees F thus far. Only frustration is have to keep it quite level to keep the water from syphoning out. Using it in a mobile chicken coop, so have to keep a variety of boards in the pen to prop up the waterer to keep level.