I managed to keep these working for 20 months with a lot of repairs and awkward workarounds, but now they have broken irreparably.
First one of the magnets came off, so I glued it back on. Then one of the ear tips started coming off and getting stuck in my ear. I found that if I pressed my finger on the tip while I was pulling it out of my ear, that would make it come out properly most of the time, but not always. Sometimes the tip would come off and fall on the floor, but by luck I managed to find it again each time. Eventually, of course, luck always runs out.
Then the other ear tip started coming off in the same way as the first one.
Then one of the plugs completely fell apart into three pieces. I glued it back together.
I used these ear protectors twice after that. The second time was today. After I had finished playing, I let them stick together with the magnets as usual around my neck. When I tried to take them off, one of the magnets ripped off the other one, along with part of the filter assembly. The membrane is now torn and the thing is therefore beyond repair.
If these things had been amazing in other ways, I might have felt differently about this, but the truth is that the frequency response was not as even as the manufacturers claimed. They would also have a habit of wiggling loose, meaning that the amount of protection I got turned out to be fairly random. As for the attenuation controls, in the end I never needed any more than the minimum. I had been hoping that they would allow me to reduce the attenuation much further so that I could hear verbal instructions in between blasts of percussion, but they didn't. So that feature that had been one of the reasons I had payed big money for these things turned out to be useless.
The only advantage these things had over other in-ear ear protectors I have owned in the past was the cord because it stopped me losing the things when they fell out of my ears (which did happen a few times). In other words, I spent €140 on this poorly made crap when I could have got just as good for €20. Big waste of money.