Bio3 Emperor 280 and 400 Filter Cartridges Regular 4 pk

3-stage filtration in a single cartridge Baffle floss filter bag prevents carbon from settling Clamshell frame locks securely to contain filter media Disposable, baffle floss/carbon bag provides mechanical and chemical filtration and prevents carbon from settling. Also includes one reusable aerobic sponge for superior biological filtration and one reusable clamshell frame for easy slide-in installation in Emperor 280 and 400 filters.Please click on "More Information" for installation instructions.