The Tank Filter Three Stages delivers cool, crisp water that is free of germs and other unhealthy sediments. The filter purifies your water in Three stages. In the 1st stage, its unique cellulose fiber five-micron sediment cartridge removes impurities and pests like dust, insects, dust sand and slit. In the 2nd stage, the 1micron carbon ROM film of cellulose fibers, and the inner carbon block instantly absorbs organic materials, chlorine, and its derivatives. Granulated active carbon of the filter absorbs harmful gasses and does a full recheck of the previous two cycles in the 3rd stage.