The QEE_GX is used with Zurn® Non-Barrier PEX® tubing in potable water applications. Not for use in reverse osmosis systems or in areas with known localized aggressive water chemistries. Manufactured from EcoBrass®,C69300. These fittings, as a system with Zurn® PEX® tube and Zurn® PEX® reinforcing rings are pressure rated at 160 psi at 73 deg F, 100 psi at 180 deg F, and 80 psi at 200 deg F. These fittings are 3rd Party certified as complying with the following standards: NSF/ANSI Standard 61, NSF/ANSI Standard 372 (Low Lead), ASTM F1960, CSA B137.5.