Elite Foam Cartridge for Hush 20 Power Aquarium Filter, 2-Pack Hush 20 foam inserts is an effective mechanical media that removes debris from the aquarium It encourages populations of beneficial bacteria that are important in maintaining the proper biological balance in the aquarium Includes 2 cartridge per pack Measures 1-inch length by 4-1/2-inch width by 6-4/5-inch height This product weighs 0.02-pound