The Valley Industries universal 100 PSI bottom mount 2" Gauge was designed to be used for applications such as gas, oil & water or any medium not corrosive to brass or bronze. Featuring a brass movement with phosphor bronze bourdon tube. Built with an acrylic window & abs standard steel for increased durability. 1/4in MNPT 316 brass Male connection. Grade B accuracy. Black enameled aluminum Pointer & white background. Fill made of dry material only.