Zip HydroTap 0.2 Micron Filter Replacement Cartridge for G4 models only removes sediment, chlorine, heavy metals like lead, impurities, plastic fibres, bacteria and parasites greater than 0.2 microns. This eliminates taste, odour, lead and impurities in the water. A filter change warning light on the HydroTap G4 flashes to show when a filter change is due. Filter replacement at least once each 12 months is recommended.