With the XXL 2500-liter Grohe Blue filter cartridge, you can turn regular tap water into delicious table water. During the five purification stages, the water quality and taste are continuously refined, removing all unwanted substances. Heavy metals and even the finest particulates are filtered out, and the lime content is reduced. What remains is pure, delicious water for you to enjoy. Changing the cartridge is incredibly easy: simply unscrew the old filter cartridge, insert a new one - and you're done.