A housing for an apparatus for portable wireless transmission, the apparatus for portable wireless transmission having an antenna element arranged to be able to resonate at a particular highest resonant operating frequency to send/receive transmissions substantially in a significant radiating direction. The housing comprises one or more metal piece areas arranged to, when assembled with the apparatus for the portable wireless transmission, be located over the antenna element in a significant radiating direction in electrical isolation from an electrical ground of the apparatus. The metal piece area(s) comprise a plurality of metal pieces arranged with the housing to be substantially electrically isolated from surrounding metal with dimensions having effective lengths of at most five-tenths of a wavelength for the highest resonating operating frequency of the antenna element.