Our HF20-S water filter contains a compressed carbon block, which provides tremendous capacity to remove and/or reduce impurities and sediment that may be present in your drinking water. The carbon block has millions of active sites on its surface and within the structure, which can absorb impurities like a sponge, and can adsorb and hold other types of impurities on its surface like a magnet. Additionally, this filter can catalytically break down other impurities, similar to how a catalytic converter works in your automobile. These processes ensure that you are getting the cleanest and best-tasting water possible. HF20-S HF20-MS HF25-S Water Filter Replacement HF20-S Water Filter replacement cartridge Compatible with HF20-S, 5615103/HF20-MS, 5615109/HF25-S,5615203, Water Filtration System. Filter Life (Months): 12 Filter Life (Gallons): 9000 Flow Rate: 1.5 gpm Operating Pressure: 25 - 125 psi Operating Temperature: 40 - 100 ° F