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, Recommended Use Air, gas, oil, water, Range PSI 0-1,000, Movement Brass, Accuracy ASME/ANSI B40.1 Grade A 2-1-2, Mount Type Back, Dial White Aluminum, Fill Material Glycerin, Connection Size in. 1/4 Male NPT, Gauge Diameter in. 2 1/2, Bourdon Tube C-shaped, Window Material Temperature compensating polycarbonate, Max. PSI 1,000.