Danner Manufacturing, Inc., Supreme Aqua-Mag Air Fractionating Water Pumps are the ideal pump choice for the aquarium hobbyist looking to maximize dissolved oxygen levels in their freshwater or saltwater aquarium. The pumps' uniquely designed shaft and impeller design breaks up the in-flowing water and creates tiny bubbles that add vital oxygen to the aquarium water. The pump is equipped with a reusable debris pre-filter and a 18" vinyl aerating tube with Noise-Suppressing muffler that allows for reliable and quiet use in aquariums of all sizes. The Aqua-Mag Air-Fractionating Water pumps will operate efficiently submerged or in-line and are particularly ideal for saltwater / reef aquariums with their ceramic shaft design and adjustable, front-mounted venturi. Includes Adjustable Venturi and features a fractionating impeller design that adds vital oxygen to Aquarium Water.