Marineland Penguin Rite-Size C Bio-Wheel 170, 200, 330 & 350 BULK Replacement Filter Cartridge (6-Pack) The Rite-Size C Marineland Penguin BULK Replacement Filter Cartridge (6-Pack) is for the Penguin Bio-Wheel 170, 200, 330 & 350 Power Filters For best results, change every 2-4 weeks. We've removed the product from the packaging. Doing this lowers the shipping cost, and we pass on the savings with a lower product price.