Bioscape Air Pumps are designed to increase water movement in aquariums for proper oxygenation. Available in 6 sizes these high quality air pumps operate quietly and efficiently. Ranging from single, dual and quad outlets there is a size suitable for all aquariums types up to 600L. The two largest sizes have an adjustable air flow. The Bioscape Tropic Air Pump range also comes with a free check valve for each outlet for added value to your aquatic customers.