... size:1.5", 2", 2.5", 3, 3.5", 4", and 4.5", 6", 8", 10",Pressure range:-30" Hg-0 ... -10,000PSISocket:Brass bottom and back connection ,side connectionConnection thread:NPT , BSP, BSPT and other special specificationBourdon tube:Brass or ... steel or chrome plated steelWindow (lens):Glass, acrylic, and polycarbonate lens availableDial plate:Single and dual scale (psi, kpa, mpa, bar, kg ...