Fluval Quick-Clear is specifically designed to fit the Fluval 307/407 and 306/406 canister filters. These thick, ultra-fine polyester water polishing pads effectively trap micro particles and debris, leaving your aquarium crystal clear. Key Features : *Maximum Mechanical filtration *Traps micro-particles and debris for sparkling water *Ideal for use in cloudy aquariums or after routine maintenance *Specifically designed to fit the Fluval 307/407 and 306/406 canister filters *For best results when clearing a cloudy aquarium, use in conjunction with Fluval Cloudy Water Treatment (A8366) *Convenient 6-pack format *For use in freshwater and saltwater aquariums