These compact, energy efficient, quiet corner filters are cleverly designed for high volume mechanical and biological filtration to help keep water crystal-clear. Integrated diffuser with three adjustable water flow settings – Allows for uniform surface movement, prevents formation of biofilm, and provides added aeration Simple cleaning and maintenance – Remove individual filter modules while keeping the pump unit in place for easy cleaning and maintenance Carbon filter foam – Activated carbon absorbs unwanted substances in aquarium water. Carbon filter foam make replacement much simpler than using common granular carbon.