Key Features Powerful Internal Aquarium Filters, For Aquariums up to 300L Easy Click in media Cartridge Spray bar and adjustable flow rate Dual Action Filtration with Foam and Carbon 2 Year Guarantee SuperFish Aqua-Flow internal Filters are a compact and powerful internal filter with an easy to replace media system Available in a selection of sizes, the filters are slimline and sit neatly on the side of your tank under the water line. Each filter has a spray bar that when placed above the top line of water will produce a calming bubble effect while adding vital oxygen to the water. The water flow is easily adjustable with the front located flow control button (not available on Aqua-Flow 50). Allowing you to control your filtration system. Each Aqua-Flow as a unique easy click in cartridge that has a dual action filtration set up. 1 cartridge is filled with media foam and activated carbon. It is recommended this is changed every month The second cartridge is filled with CrystalMax, a