My husband purchased the wrong size. New in Box. Recently purchased.
Tetra Whisper Filter Cartridges help keep aquarium water sparkling clean. Ultra-Activated carbon removes odors and discoloration. Use these small replacement filter cartridges in your Tetra Whisper . These filters are ready to use for your convenience. To install, first rinse the cartridge under cool tap water until the water runs clear. Insert cartridge into the filter. Pack contains 6 small replacement cartridges. An aquarium filter not only cleans the water your fish breathe, but it also keeps your tank looking pristine. Trust your tank to Tetra brand filtration products for cleaner, healthier water and happier fish. Since 1951, Tetra has developed the world's most comprehensive body of fish food knowledge, and fishkeeping enthusiasts have looked to the brand for products and solutions that add ease and beauty to their home. Whether you're an experienced hobbyist or just starting out, Tetra has everything you need from a large variety of quality fish food and innovative equipment to test kits and decor.