Marineland Penguin Rite-Size Cartridge A, 1 pk (PA0135) Rite Size Cartridge A meet the absolute highest standards of water purification Fits Penguin 100B, Bio-wheel Mini and Penguin 99B power filter This preassembled cartridge slides easily into place Providing superior mechanical and chemical filtration and making replacement fast, dry and effortless Debris and waste particles are trapped and water is chemically filtered through Marineland' s Black Diamond premium activated carbon