Detailed Product Description General Pressure GaugeDiameter: 1-1/2", 2", 2-1/2", 4", 6"Case: black steel, plasticWindow: glass, acrylic ... or stainless steel Connection: brass Connection size: 1 / 8" 1/4" 3/8" 1/2"NPT, BSP, BSPTPressure Range: 0-30Psi ... 1.5 purposes: Measurement static, or copper and copper alloy non-corrosive, non-explosive, non-crystalline, not precipitate the gas or liquid pressure ...