APEC ULTIMATE Series high capacity 6-stage complete filter set is USA made and designed to last 2x longer, use with APEC RO-PH90 or systems with pH enhancer kit upgrade Includes(1) Sediment,(2) Carbon block filters,(1) Dow Filmtec Membrane, (1) Inline carbon filter and (1) pH+ Calcium Carbonate Re-mineralization filter Filmtec 90 GPD membrane is individually lab tested to guarantee the highest rejection rate Certified to remove up to 99% of all contaminants for the best drinking water quality possible 10" pH+ Calcium Carbonate Re-mineralization Filter adds food grade calcium minerals to enhance water taste