Model 6424 Brita® Hydration Station® replacement filter cartridge is used on models 2000 and 2000SM systems which are tested and certified by CSA International against NSF/ANSI Standard 42 for the reduction of chlorine (taste and odor) and against NSF/ANSI Standard 53 for the reduction of lead and cysts. It is a 2,500 gallon (9463 L) capacity carbon block filter cartridge.