Penn-Plax Cascade 300 GPH Hang On Filter Replacement Media, 3 Pack - Dual-Sided Aquarium Filter Cartridge with Activated Carbon & Poly-Fiber Floss for CPF5 -Fresh & Saltwater - Blue & Black, ‎10x3x7inBrand: Penn Plax Features: Sparkling Water Made Simple Dual action aquarium filter cartridge designed for Cascade 300 GPH hang on filters. Activated carbon removes discoloration and odors while the poly fiber layer traps particles keeping your fish tank water clean and clear. Healthier Habitat for Fish These filter cartridges provide efficient filtration for both freshwater and marine aquariums, helping maintain a balanced and stable aquatic