Review on 🔩 SUNGATOR 12-Pack Push Fit PEX End Cap: 1/2-Inch Push-to-Connect Plumbing Fittings with Disconnect Clip - Lead Free Brass for Copper & CPVC by Charles Mathews

So they work IF you install them correctly. I say this because I once had a burst hot water pipe thinking I had it hooked up correctly. And I've found that if you're doing a temporary cap install mid-work, it's probably better to use a shark-bite valve shut-off fitting for capping, as it means you don't have to remove the cap to test the work downstream . In summary, the caps are fine, but I will most likely not be buying any more as I don't plan on leaving plexiglass or copper wires with the caps in place for long periods of time. If small children and/or irresponsible adults are around your project, you can use these caps in place of the more convenient shut-off valve equivalent.