One of two valves would not fully close and made a pressure test impossible. The handle physically would not rotate all the way to the stop, and from looking through the inside it appears that it has almost no travel past the point where it initially closes. Luckily I had a spare to use for a replacement which did perform. This defect would have easily been observed if there had a final inspection, and would certainly have been caught if the finished valve was pressure tested. Otherwise, the fit and finish of the valves is excellent and the gasket seal to the manifold was perfect. Hopefully this was a fluke, in an otherwise solid product as I don't know what else one would use with the Mr Pex manifolds