Detailed Product Description Gas Test Gauge Diameter: 2"Case: steelWindow: glassInternal: brassInlet thread: 1/8", 1/4" NPT ,BSPT, BSP, steel chrome plated gas test body.Connection: bottom connection, center back male connectionRange: 0~15psi,0-30psi or according to customer orderScale: psi, bar, Mpa, Kpa, kg/cm2, Hg single or dual scale or according to customers order.Accuracy: 2.5%, 1.6%