Rite-Size Z fits Eclipse Explorer, Eclipse System Three, Eclipse Hex 5, Eclipse Corner 5, and Hex 7. Each pre-assembled cartridge slides easily into place, providing superior mechanical and chemical filtration, and making replacement fast, dry and effortless. The cartridge mechanically filters water through a pad of double thick poly-fiber. Debris and waste particles are trapped, and water is chemically filtered through Marineland's Black Diamond Premium Activated Carbon.