1.all ss pressure gauge 2.brass internal 3.63mm 4.accuracy 1.6% PRESSURE GAUGEDial size:1.5",2.0",2.5"Pressure Range:-30-0-10000psiSocket:brass bottom connectionConnection thread:NPT , BSP, BSPT and other special specificationBourdon tube:stainless steelCase:304 stainless steelBezel:304 stainless steelWindow:glass window or plastic windowDial plate:single and dual scale(psi,kpa,mpa,bar,kg/cm2),availableAccuracy:1.6%,2.5%,1.0%