This set of three replacement filter cartridges are for use with the 'La Cafetière' Water Filter Kettle (please see item 17894 for the La Cafetière Water Filter Kettle). Each cartridge filters sediment, pesticides, chlorine and metal particles, and each filter cartridge lasts twice as long as ordinary filters! In fact each unique 'double life' cartridge lasts up to 60 days, and the kettle even has an electronic reminder when it's time to replace the cartridge.