The Aquael Pond Heater 150 watts Keeps ice at bay in your pond. Keeps an area of the surface free from ice, enabling: Vital oxygen into the water. The release of toxic gases from the water caused by breakdown of vegetation and waste matter. Provides Birds with a vital source of water during the winter period. Features: 10 metre outdoor cable for safe connection to power supply. Stainless steel casing with protective circulation cover for quick and efficient heat transfer. 150 watt or 300 Watt element for economical use. Protected float for better efficiency and keeps it at the surface.