This ASTM/ANSI/ASME-certified, class 150, 3/8-inch square head plug has an MNPT connection type. It is used in air, natural gas, oil, potable water, and steam-based applications and is made of 304 stainless steel for good corrosion resistance. This product has a maximum operating pressure of 150 PSI and temperature range between -30 Degrees F to 320 Degrees F.