Culligan Direct Connect Standard-Replacement Cartridge. For use in US-DC1 (SKU 404465) and US-DC2 systems. Reduces chlorine, taste and odor from the water at your faucet. Replace filter easily in seconds. Change every 6 months or 2,000 gallons. Adheres to NSF (National Sanitation Foundation)/ANSI (American National Standards Institute) 372, CSA (Canadian Standards Association) B483.1 42 and 53.