Quiet, economical filtration performance of the classic Whisper 40 Power Filter is great for freshwater or saltwater aquariums. Energy-efficient designs feature low-wattage motors and adjustable flow control. Bio-Foam cultivates and maintains a bacterial bed for biological filtration, while easy to replace Bio-bag cartridges take care of chemical and mechanical filtration. Bio-Bags included. Measures: 8 in. x 4.5 in. x 7.5 in. The Whisper 40 is rated for aquariums up to 40 gallons, and has a maximum flow rate of 210 gph.