Elite Carbon Cartridge for Hush 35 Power Aquarium Filter, 2-Pack Elite hush 35 pre-filtration pad polishes aquarium water while the activated carbon removes discoloration and odors The easy to use disposable cartridge should be replaced monthly Includes 2 cartridge per pack Measures 17-1/2-inch length by 5-1/2-inch width by 8-4/5-inch height This product weighs 0.63-pound