Forney 87727 Oxygen Gauge, High Pressure, 2-Inch-by-1/4-Inch NPT, 0-4000 PSI High pressure gauge for oxygen regulators High pressure gauge with 0-4000 PSIG 2-Inch face with 1/4-Inch national pipe thread NPT Features threads that are common to Forney, Victor, Harris, Smith and Marquette style regulators Solid brass threads and brass casings provide extra long life