Detailed Product Description Dial1.5" (40mm),2"(50mm),2.5"(63mm),4"(100mm),6"(150mm)CaseStainless steelLensGlass / PolycarbonateRingCrimped on / bayonet bezelFill LiquidGlycerin or Dry but fillableInternalBrass / stainless steel / stabilizer movementsConnection 1/4" or 1/2" NPTRange30" Hg Vac/Kpa -- 0-20000 Psi/KpaAccuracy±2%,±1.5%,±1.0%