"Brass movement with C shaped Boudon tube. 1/4in. NPT male connection. For use with air, gas, oil or water. Black enameled aluminum pointer, white aluminum dial and temperature compensating polycarbonate window. Glycerin filled to dampen pulse and vibration. Accuracy ASME/ANSI B40.1 Grade A 2-1-2. Pointer Black enameled aluminum, Connection Size in. 1/4 Male NPT, Accuracy ASME/ANSI B40.1 Grade A 2-1-2, Recommended Use Air, gas, oil, water, Window Material Temperature compensating polycarbonate, Bourdon Tube C-shaped, Fill Material Glycerin, Range PSI 0-1,000, Dial White aluminum, Movement Brass, Max. PSI 1,000, Gauge Diameter in. 2 1/2, Mount Type Back."