POWERHEAT DE-ICER, Keeps an area thawed, preventing the pond from completely freezing and allows for crucial gas exchange, Safe for plastic and liner ponds, will not harm fish, Made from stainless steel which gives it an extremely high impact resistance over plastic models, Temperature is controlled by 4 interacting ntc thermistors which sense temperatures at 4 different locations within the unit, , UPC : 015561216432, Size : 500 WATT, Product Type : Pond - Filters, Pumps & Accessories / Heaters And Deicers SKU: BC013568