Stainless steel case Brass internal Glycerin filled Back connection Good quality Liquid filled Pressure Gauge:Case sizes: 1.5", 2", 2.5", 3", 4" and 6" Case material: stainless steel case, it can take with front flange, back flange and U-clamp Bezel material: stainless steel bezel, stainless steel roll ring or bayonet ring Tube and socket: phosphor bronze and brass Movement: brass Liquid: ...