This ANSI/ASME-certified, class 150, 3/8 x 1/8-inch reducing coupling has an MNPT x FNPT connection type. It is used in air, natural gas, oil, potable water, and steam-based applications and is made of 316 stainless steel for excellent corrosion resistance. This product has a maximum operating pressure of 150 PSI with a temperature range of -30 Degrees F to 320 Degrees F.