APEC Ultimate high flow 5-stage complete filter set is made in USA with the highest quality filtration components to provide a longer lasting filter set to protect and prolong the lifespan of your reverse osmosis system. Premium quality pre-filter cartridges lasts over 12 months while the membrane and post carbon filter last 3-5 years for fewer filter change outs and high performance contaminant removal. These standard size filters are compatible with APEC RO-45, RO-PUMP, and all other 10" standard size under counter 20-50 GPD RO systems on the market. APEC Ultimate super capacity 5-stage complete filter set is USA made and designed to last 2x longer Includes(1) Sediment,(2) Carbon block filters,(1) Dow Filmtec Membrane and (1) Inline carbon filter Filmtec 50 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 Compatible with most under-counter 20-50 GPD RO systems on the market