Fluval® Fine Filter Pads are specially designed to fit Fluval® FX5 High Performance Canister Filters. These polyester pads capture small particles and debris that can cloud water, and help maintain clear water. The Fine Filter Pads should be used in conjunction with Fluval® Water Polishing Pads to optimize the purity of aquarium water. For freshwater and marine environments. Includes three filters pads in a pack.