Graham-White Custom Pressure Gauges have long been the standard technology for both the heavy rail and rail transit industries. From a pressure stand point, our unique Duplex Pressure Gauge series is an extraordinary single gauge that delivers two separate pressure readings simultaneously. This dual function does the work of two single gauges, requires half the panel space, and costs less. The 785 & 786 Series 4" Duplex Air Gauges are designed with high quality bronze bourdon tubes and precision phosphor bronze movements for optimum performance and reliability. Black or green dials with white numerals (0-160 and 0-200 PSI scale) are standard. An integral quick disconnect and test feature makes all GW gauges easy to install within your control stand or console and inspect in place using the GW 706-000 Air Gauge and Pressure Switch Tester. All gauges can be removed for servicing without breaking any pipe connections. An assortment of GW "Quick Disconnect" Test Fittings are available for quick and easy testing of stand-alone air gauges and pressure switches.