... Use RangeRelative humidityProtection Scope60%-55%classics,old paintings and antiques,coins,stamps,copy paper,fax paper,printing ... ,camera lens,microscope,telescope,CD,positive and negative film,musical instruments,fur,medicines etc45%-35%Non-ferrous ... ,batteries etc35%-25%Precision measuring tools,optical instruments,a light source,detector,lenses,lens,pharmaceutical raw materials science.25 ...