All penguin bio--wheel power filters deliver simple, easy, 3-stage aquarium filtration without the hassle of air pumps, valv. Penguin filter maintenance is fast and easy and the bio wheel never needs replacing. Each Contains New Faster-Acting Black Diamond Premium Activated Carbon For Maximum Efficiency. Biological Filtration Is Provided By The Revolutionary Bio-Wheel - Proven Best At Removing Toxic Ammonia And Nitrite. 100 GPH