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