RVRCIL Carbon Block Reverse Osmosis Water Filter Set Taste Enhancement : This set of two 5 micron carbon block Reverse osmosis water filter cartridges is effective pre-filtration for both chlorinated (municipal) and private well (non-chlorinated) water. The 32-250-125-975 carbon block cartridge is manufactured in the U.S. It can remove dirt sediment down to 5 micron and absorb chlorine / chloramine and other chemicals providing superior reverse osmosis membrane protection. This cartridge set should be replaced every 6-12 months. Universal 2.5 x 9.75 inch dimension Rigid extruded carbon block construction Removes disinfectants that damage thin film composite membranes This package includes an additional stage 4 post filter. This in-line filter contains 50% calcium carbonate mineral and 50% granulated activated carbon. The purity of reverse osmosis water can impart a non-desirous flat taste. This cartridge enhances the ro product water taste by adding a small amount of calcium carbonate mineral and providing final stage carbon filtration