Cambridge Aquatics Filter Cartridge Replacement for Aquatics Power Filters , 5-20-Gallon, 3-Pack Replacement filter cartridges for Cambridge Aquatic power filters Contain activated carbon to remove chlorine and odors 5 to 20-gallon and 3-pack of cartridge Measures 8-1/3-inch length by 3-1/2-inch width by 1-1/2-inch height