The tetra whisper 20-40 internal filter for aquariums is the ultimate in quiet， convenient 3-stage filtration. The air pump (included) provides bubbles that move water through the filter， efficiently filtering and oxygenating your aquarium. The water flows through ultra-Activated carbon， absorbing odors and discoloration， as well as through the dual-sided mesh of the bio-Bag filter. Each unit includes the filter， air pump， 2 feet of airline tubing， and one tetra whisper bio-Bag filter cartridge.

• INTERNAL FILTER: Mounts on the inside of your aquarium with a clip (included).
• CATCHES DEBRIS: Dense， dual-sided mesh filters debris and fish waste.
• AERATES WATER: Air-driven design filters water while oxygenating water.
• CONVENIENT DESIGN: Uses easy-to-change bio-Bag cartridges filter mounts inside the aquarium， making it possible to place the tank flush against the wall.