Key Features Reliable and powerful aquarium water pumps Adjustable water flow control Energy efficient Can be used dry mounted as well as underwater 4400 LPH (968 GPH) OptiMax Aquarium pumps are a powerful and compact range of pumps from Oase. Ranging from 300 to 5000, these pumps are just want you need for any size aquarium. Each pump is made in a robust and tough casing, able to withstand years of use. The water flow can be easily adjusted to ensure the correct match with the size and occupants of the tank. The OptiMax pumps are perfect for efficient water circulation or for operating an aquarium filter. The 800 - 5000 range of pumps are slightly larger and are just as reliable. The flow control is positioned at the base on the 800 and 1000 models, but on the top of the 2000 - 5000 models. This makes it easy an convenient to use. Each pump has 4 suction feet at the base to make them easy to secure and these larger pumps can be used underwater as well as dry mounted. All OptiMax