Large, low-profile pond de-icer resists tipping against blustery winter winds. The unique design of the Pond Saucer minimizes heat loss due to frigid winds for reliable performance. Maintains a vent hole in the ice to ensure proper gas exchange throughout the winter. Thermostatically-controlled de-icer operates only when necessary for reliable energy-efficient performance – turns on automatically at 35°F and turns off when the water temperature is at 45°F.