This nut meets the standards for NSF 61 Annex G, has a length of ¼ inch, a maximum operating pressure of 400 psi and is designed for the following applications: potable water. It has an operating temperature of 65 Degrees F to 250 Degrees F, and is made of brass. In addition, it is a nut, with an imperial system of measurement, and ⅜"-24 thread. Plus, it has a compression connection type and 7/16 inch hex size.