Surface aerators are the highest oxygen producing and highest volume aerators offered. For applications desiring maximum flow and efficiency these units are the best choice! 50' power cord standard, longer lengths available. Designed for continuous duty operation in fresh or salt water. Thermal overload protection with automatic reset. Easy to install or remove ?? making it great for portable emergency operation. Warranties ?? two years on 1/2 - 1 HP, three years on 2 - 5 HP. Operates in as little as 15"of water. Because of their high pumping rates these units are especially helpful in controlling floating debris, duckweed and other unsightly surface problems. A high oxygen transfer make these units the best pick for aquaculture applications and wastewater ponds.