... the multi-channelpolishing process, so that the surface bright, if any scratches and defectshave to be re-polished. (5) ... resistance, wear and tear functions.(7) Polished plating, to enhanceaesthetic degree.(8) Is suitable for wooden doors, ... square wave and oblique tongue , so as to ensure that in caseof emergency escape rapidly from the indoors.( ... .If you have any question, pleasegive me ring online.