... 2.5",3",3.5",4",4.5",and 6"pressure range:-6...0 mbar up to 0... ... ss phosphor brassconnection way:back connection,bottom connection ,and clamp fixing,falaned fixing thread,hose etc.connection ... sswindow(lens):polycarbonate,and safety glass lens availabledial plate:single and dual scale(psi,kpa,mpa,bar,kg/cm2)availableaccuracy:+/- ... relative humidity below 80% dual scale diaphragm pressure gauge 0-30PSI