Culligan D-10A Cellulose Impregnated Basic Drinking Water Filtration Replacement Cartridge, 250 Gallons (2 Pack) N/A Made in USA The D-10A cellulose impregnated basic filtration replacement cartridge works as a replacement filter cartridge for the Culligan US-550, SY-2000, SY-2100 and US-600A Provides cleaner better tasting water for cooking or drinking The D-10A filter cartridge reduces: Chloride and removes bad taste and odor from water along with particulates class III The US-600A with D-10A is Tested and Certified by NSF International against NSF/ ANSI Standard 42 for the reduction of aesthetic Chlorine Taste and Odor and nominal Particulate Class III The D-10A cartridge can filter up to 250 gallons of water or can last for 3 months Water flow rate from faucet, 1 gpm at 60 psi *Some harmless bacteria may attack the cellulose media in the D-10A producing a musty moldy odor, if so switch to a synthetic media cartridge