The QER_X is used with Zurn® Non-Barrier PEX® tubing in potable water applications. Molded from PEX® with integral positioning tabs. These expansion reinforcing rings, as a system with Zurn® PEX® tube and Zurn® PEX® fittings are pressure rated at 160 psi at 73 deg F, 100 psi at 180 deg F, and 80 psi at 200 deg F.