Magnehelic diffential pressure gauges for scale from 0 – 250mm of water. High accuracy ±2% of full scale. Die cast aluminum case and bezel housing, with acrylic cover. 4″ Diameter dial face. Pressure Limits: -20 in Hg. to 15 psig.† (-0.677 bar to 1.034 bar). Temperature Limits: 20 to 140°F (-6.67 to 60°C). Mounting Orientation: Diaphragm in vertical position. 1/8″ female NPT connection.