Detailed Product Description Vacuum GaugeDiameter: 1-1/2", 2", 2-1/2", 3", 4", 6"Case: stainless steelWindow: polycarbonateInternal: brass, stainless steelInlet thread: 1/8", 1/4", 3/8", 1/2", NPT ,BSPT, BSPConnection: center back male connectionAccuracy: 2.5%Scale: psi, bar, Mpa, Kpa, kg/cm2, Hg single or dual scale or according to customers order