Marina Slim Filter Carbon Plus Ceramic Cartridge, (3 Pack) 

• Replacement: Marina Slim Filter Bio-Carb is a genuine replacement cartridge for all three Marina Slim Filter Models (S10, S15, S20).
• Ideal Usage: Ideal for tropical fish, the filter cartridge contains activated carbon and Ceramitek for optimum filtration and a healthy aquarium.
• Helpful Filtration: The activated carbon effectively removes pollutants and odors from your aquarium water. Ceramitek, a highly porous ceramic biological filter medium, optimizes biological filtration.
• Easy Installation: The easy-to-use disposable cartridge should be replaced every two weeks for the best results. Never replace all filter cartridges at the same time to ensure a constant presence of beneficial bacteria.
• Multi-Pack: Includes 3 replacement filter cartridges.