The brita classic cartridge reduces limescale chlorine and other impurities giving cleaner clearer great tasting hot and cold drinks fits all brita classic jugs approx 1 month supply per cartridge suitable for all water types 100 recyclable the brita classic cartridge reduces limescale chlorine and impurities change the cartridge every 4 weeks for best results fits all brita classic jug systems brita cartridges are 100 recyclable