"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. Accuracy ASME/ANSI B40.1 Grade A 2-1-2, Mount Type Stem, Connection Size in. 1/4 Male NPT, Range PSI 0-160, Recommended Use Air, gas, oil, water, Gauge Diameter in. 4, Fill Material Glycerin, Pointer Black enameled aluminum, Dial White aluminum, Window Material Temperature compensating polycarbonate, Bourdon Tube C-shaped, Movement Brass, Max. PSI 160."