These filter cartridges remove odors and impurities from the water for a pure aquatic environment. The easy to assemble Bio-BagsA make aquarium maintenance easy. Clean your aquarium with the power of Ultra-activatedA carbon in these Tetra Whisper Bio-Bag Disposable Filter Cartridges. The highly absorbent carbon removes odors and discoloration, while dense mesh catches debris to provide clean, clear water for your aquatic pet. With the easy-to-use, maintaining a pure aquatic environment is a cinch. Highly-absorbent carbon removes odors and discoloration for clean, clear aquarium water Dense, dual-sided mesh catches debris and fish waste to help maintain purity Convenient, easy to assemble Bio-Bags are easy to use For best results change Bio-Bag monthly Cartridges are available in medium (10i, E, J, 10 and MicroFilterTM power filters) and large (20i, 40i, C, 20, 30, 40 and 60 power filters) sizes