Keep your aquarium clean and clear with the Tetra Whisper Bio-Bag Filter Cartridges. Designed for all water types, these filter cartridges fit perfectly into internal filter locations and are ideal for tanks up to 60 gallons. The pack includes three medium-sized cartridges, which are made with high-quality materials in the United States. These filter cartridges are specifically designed to keep your aquarium water crystal clear and healthy for your fish and plants. With a brand that is trusted by aquarists worldwide, these Tetra Whisper Bio-Bag Filter Cartridges are an excellent choice for maintaining your aquarium's cleanliness.