Check the listing for details. Aqueon QuietFlow Replacement Filter Cartridge Large 6 pack. Condition: New. Listed at 24.99 USD. Aqueon QuietFlow Replacement Filter Cartridge Large 6 pack Aqueon Replacement Filter Cartridges are dual-sided, featuring dense-floss with over 25% more activated carbon than the leading brands. These patented cartridges were designed to ensure even distribution of activated carbon. To use, simply rinse under cold water and easily install using the FRONT orientation tab. Cartridge contains high quality activated carbon that keeps water clean.Installs in seconds: rinse first and align cartridge bottom key slot for an accurate fit inside the Filter.Easy installation using the FRONT orientation tab.For optimal performance, change approximately every 4 weeks.Fits Aqueon QuietFlow Filter: LED PRO Size 20, 30, 50 and 75, Power Filter Size 20, 30, 50, 55/75, E Internal Size 40, Canister Filter Size 200, 300 and 400Size: Large, 6 pack