Fluval FX4/FX5/FX6 Max-Clean Fine Filter Pad. Designed specifically for Fluval FX4, FX5 and FX6 canister filters, these polyester Fine Filter Pads capture small particles and debris that can cloud water. Key Features : Mechanical filter media Use along with Fluval Water Polishing Pads (A246) to optimize water purity Convenient 3-pack format Specially designed for Fluval FX4, FX5 and FX6 high performance canister filters For freshwater and saltwater environments.