"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. Mount Type Back, Gauge Diameter in. 2 1/2, Movement Brass, Max. PSI 400, Pointer Black enameled aluminum, Range PSI 0-400, Bourdon Tube C-shaped, Dial White aluminum, Connection Size in. 1/4 Male NPT, Window Material Temperature compensating polycarbonate, Accuracy ASME/ANSI B40.1 Grade A 2-1-2, Fill Material Glycerin, Recommended Use Air, gas, oil, water."