Aerators for faucets; Air cleaning apparatus; Air deodorising apparatus; Air purifiers for automobiles; Air purifiers for household purposes; Air sterilizers; Apparatus for filtering drinking water; Apparatus for purifying tap water; Domestic water filtering apparatus; Drinking water filters; Electric water purification filters for household purposes; Faucet filters; Faucets; Hand held shower heads; Water filtration and purification units and replacement cartridges and filters therefor