Aqueon Specialty Filter Pads are designed to address common water issues. The pads are pre-cut to fit in the Aqueon QuietFlow LED PRO Power Filter Bio-Media Grid. There are three varieties available in three sizes: Ammonia Reducing Carbon and Phosphate Remover. Each come in a 4 Pack. Aqueon products offers a wide range of items so that you can build and maintain a healthy aquatic environment. All the essentials from fish tanks filters lighting food care and other supplies that your pet fish needs. We make it easy for you to get your first aquarium and to grow in the hobby as you become more of a fish expert with every step you take and every new thing you learn. For those seasoned hobbyists we are committed to aquarium product innovation so that we continue to offer products that get you excited. With the Aqueon brand it s all about the fish.