Detailed Product Description Diaphragm GaugeCase: stainless steelWindow: polycarbonateInternal: stainless steelInlet thread: 1/8", 1/4", 3/8, 1/2", NPT, BSPT, BSPConnection: bottom connectionRange: 0~6000psiScale: psi, bar, Mpa, Kpa, kg/cm2, Hg single or dual scale or according to customers order.Oil composing: glycerine, silicone oilAccuracy: 2.5%, 1.6% 1%