Marineland Penguin 350 GPH Power Filter / Cartridge Bundle Marineland Penguin 350 GPH Power Filter Plus a 3 Pack of Refill Cartridges Certified flow rate of 350GPH, perfect for all aquariums up to 70-gallon, uses two Rite-Size C" filter cartridges" Delivers easy, three stage mechanical, chemical, and biological aquarium filtration Convenient Penguin Rite Size Cartridges come ready to use with each filter