This nut meets the standards for NSF 61 Annex G, has a length of ⅜ 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/sleeve, with an imperial system of measurement, and 5/16"-24 thread. Plus, it has a compression connection type.