GE FTHPM Whole House Water Filter | Replacement for Water Filtration System | NSF Certified: Reduces Sediment, Rust & Other Impurities from Water | Replace Every 3 Months for Best Results | 1 FilterCertified to NSF ANSI 42 Certified by IAPMO Three month filter life For best filtration results, filters should be replaced every three months or 15,000 gallons. Single pack Includes one filter cartridge. Protect appliances & plumbing Sediment reduction helps equipment last longer Filters down to 30 microns The lower the microns, the more contaminants are caught and reduced