Marineland Eclipse Rite-Size H Replacement Filter Cartridge, by Eclipse Rite-Size Four Marineland Eclipse Rite-Size H Filter Cartridge 3-Packs (12 filters total) The Rite-Size H is for the Eclipse 2 and Eclipse 3 Aquarium filtration systems It also is the replacement for Marineland Glass Systems 25, 29 & 37 For best best results, change the filter cartridge every 2-4 weeks