"Brass movement with C shaped Bourdon 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. Max. PSI 600, Gauge Diameter in. 4, Range PSI 0-600, Mount Type Stem, Recommended Use Air, gas, oil, water, Fill Material Glycerin, Movement Brass, Accuracy ASME/ANSI B40.1 Grade A 2-1-2, Dial White aluminum, Bourdon Tube C-shaped, Pointer Black enameled aluminum, Connection Size in. 1/4 Male NPT."