CRYSTAL QUEST&reg; Whole House Triple 20" x 2.5" Water Filter System Water travels through 7 stages of filtration. 1st stage, Water flows through a 20" sediment filter cartridge that removes silt, sand & dirt. 2nd, 3rd, 4th,5th & 6th stages, water travels through a one micron filter pad, KDF55, KDF85, GAC, 7th stage,water flows through a solid carbon cartridge for removing volatile organic carbon compound Conveniently provides 160,000 gallons of quality water. Great for homes, apartments or office use.