Tetra Whisper Filter Cartridges 3-Pack, Medium (Internal 2-10 gal / Power Filters 5-15 gal) Maintains the performance of Tetra power filters with ultimate convenience Coarse floss layers remove large debris, keeping aquarium water clear and clean Activated carbon removes discoloration, odor, toxins other aquarium impurities Dense, dual-sided mesh catches debris and fish waste, promoting healthy fish Includes a 3-pack of medium, ready to use replacement filter cartridges