... :1.5",2",2.5",3",4",6". Black Steel Case Dual Scale Dry Pressure Gauge 1. Diameter: 1 ½", 2", 2 ... ½ ",3",4",6";2.Case: black steel case;3.Window:glass, acrylic, polycarbonate;4.Internal: brass, stainless ... oil;10.Accuracy: 2.5%,1.6%,1%. Black Steel Case Dual Scale Dry Pressure Gauge