Culligan D-20A Basic Drinking Water Filtation Replacement Cartridge, 1,000 Gallons N/A Made in USA The D-20A basic filtration replacement cartridge works as a replacement filter cartridge for the Culligan US-550, RO-2127 and US-600A Provides cleaner better tasting water for cooking or drinking The D-20A filter cartridge reduces: Chloride and removes bad taste and odor from water The US-600A with D-20A is Tested and Certified by NSF International against NSF/ANSI Standard 42 for the reduction of aesthetic Chlorine Taste and Odor The D-20A cartridge can filter up to 1,000 gallons of water or can last for 12 months Water flow rate from faucet, 1 gpm at 60 psi