304 stainless steel case center back male connection oil composing:glycerine ... :1.5",2",2.5",3",4",6". Panel Mount Stainless Steel Liquid Filled Glycerine Pressure Gauge 1. Diameter: 1 ½", 2", 2 ... ",3",4",6";2.Case: 304 stainless steel;3.Window:polycarbonate;4.Internal: brass, stainless steel;5.Inlet thread:1/8", 1/4 ... : 2.5%,1.6%,1%. Panel Mount Stainless Steel Liquid Filled Glycerine Pressure Gauge