This is the recommended alternative for the now-obsolete OmniFilter GAC1SS!
Ideal for both city and well water, the Culligan D-20A undersink water filter replacement cartridge will reduce chlorine, bad taste and odor for up to 12 months or 1,000 gal. Installs quickly and easily into undersink water filtration systems that use 9-3/4 in. x 2-1/2 in. cartridges.