APEC Water SystemsAPEC Water Ultimate complete 4-stage high capacity filter set APEC high capacity filter set is made in USA with high quality filtration components to provide a longer lasting filter set to protect and prolong the lifespan of your reverse osmosis system. Premium quality pre-filters and 4th stage filter lasts 6-12 months for high performance contaminant removal. The pre-filters effectively remove dirt, sand, chlorine, tastes and odors, extending the life of membrane as well as improving performance of the RO system.84894819854961005297