TetraTec Deep Water Air Pumps were designed to pump large quantities of air, even in deep aquariums where oxygen levels are low. They are also an excellent choice for driving protein skimmers, and have power to drive multiple airstones in one or more tanks. These Deep Water air pumps are designed for situations that produce more back-pressure for tanks up to 8 feet deep. UL listed and comes with a lifetime warranty under normal use. Made in China.