The heart of any BRITA filter system is the highest quality water filter cartridge The water filter cartridge enables the presence of limescale, chlorine & impurities to be reduced from our tap water. To achieve consistently high quality, the filter cartridges should be replaced regularly every four weeks. BRITA manufacturers four types of water filter cartridge:• MAXTRA filter cartridge for optimum performance in all BRITA MAXTRA filter jugs & partner products• Inline filter cartridge for our filter tap range• Classic filter cartridge• Multifit filter cartridge The advantages of the MAXTRA technology are the innovative combination of the natural Micropore Filter & the effective Protect Filter, which ensures excellent results from your filter system.