Internal filters that help filter water, add circulation and aeration, and polish water to keep in crystal clear. These versatile, submersible filters feature and adjustable and directional water flow output, along with an optional spray bar to distribute water evenly over the surface to aid in aeration. One bio-sponge and carbon cartridge are included. Cascade 300 Specifications: * Flow: 70gph * Power: 6W * Aquarium Size: up to 10gal. * Height: 6" Cascade 400 Specifications: * Flow: 110gph * Power: 7.3W * Aquarium Size: up to 20gal. * Height: 10" Cascade 600 Specifications: * Flow: 175gph * Power: 13W * Aquarium Size: up to 50gal. * Height: 12.25"