These are the replacement Marineland Eclipse Rite-Size Z Filter Cartridges (3-Pack) for the Eclipse System Three, Corner 5, Hex 5 and Hex 7 & all Explorer Aquarium filtration systems. They're also the replacement for the Marineland Silhouette, Contour 3 & 5 and Portrait Aquariums (Eclipse part # PA0130-03). For best results, change the filter cartridge every 2-4 weeks.
