1.black steel case / snap on plastic window/red pointer 2.brass internal 3.63mm 4.accuracy 1.6% Dial size:1.5",2.0",2.5",4.0"Pressure Range:-30-0-10000psiSocket:bottom and back connectionConnection thread:NPT , BSP, BSPT and other special specificationBourdon tube:brass or phosphor bronzeCase:ABS caseBezel:without bezelWindow:snap in plastic window,with red pointerDial plate:single and dual scale(psi,kpa,mpa,bar,kg/cm2),availableAccuracy:1.6%,2.5%,1.0%