Alwaysfresh high capacity commercial water cartridge, Certified by WQA Gold Seal NSF/ANSI std 42 & 53 for chlorine, taste, odors, turbidity, cysts, 1 micron filtration,  20,000 gallon capacity, 1.67 gpm flow. Also approved in Canada: CSA B483.1  Filter protection by Antimicrobial Silver Zeolite ions. 

Change cartridge every 6 months for optimum performance.  Also great solution for Clear Cube ice machines for Residential Applications