APEC Ultimate super capacity pre-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 filter set lasts over 12 months for fewer filter change outs and high performance contaminant removal. These standard size filters are compatible with APEC RO-PH90 and all other 10" standard size under counter RO systems APEC Ultimate super capacity pre-filter set is USA made and built to last 2x longer than other brands Includes (1) sediment, (2) carbon block filters and (1) FI-PHPLUS-QC alkaline calcite filter 1st stage 5 micron polypropylene sediment filter to remove dust, particles, and rust 2nd & 3rd stage extruded carbon block filters to remove chlorine, taste & odor 6th stage 10" high purity pH+ calcium carbonate re-mineralization inline filters w/ quick connectHigh performance replacement filters are compatible with all standard sized under counter RO systems