The Fluval fx5 is an Advanced, multi stage cannister filtration system providing maximum versatility and premium performance for aquariums up to 400 gallons. It is self starting and provides quiet and efficient operation, it is a high-capacity cannister that filters 925 gallons per hour. It was used on a salt water tank, and is in great working condition. No filter medium included. New version costs $460 at Petsmart. http://www.hagen.com/pdf/aquatic/FX5_user_manual_EN.pdf