The Seapora 1000 Overflow Prefilter is a low profile acrylic overflow box that hangs on your tank and easily converts a standard aquarium into one that is reef-ready. It comes with dual foam cylinders, a nylon u tube and a 1 inch bulkhead. The Seapora Overflow Prefilter supports flow rates of up to 1000 GPH and is ideal for tanks up to 150 gallons.