GENTEC GR20B Cryogenic Pressure Gauge applications requiring pressure readings. GENTEC GR20B Cryogenic Pressure Gauge connection 1/4” NPT.GENTEC® Pressure Gauges are manufactured to meet strictly regulated quality standards (UL404 and ANSI/ASME B40.1) and provide accuracy & reliability for use in O.E.M. and replacement applications. GENTEC® brass gauges are offered in both single scale (PSI) and dual scale (PSI & kPa) to fulfill a wide variety of applications.