They're "Davo" hinges from the album maker in the Netherlands known as "Davo". "Davos" would either be the plural of that -- or the famous ski area in Switzerland!
I did include some Davo hinges (in a red packet) in my "hinge test" of 20+ brands of hinges. They were a big disappointment as they were just like all the others. Here they are.
https://www.davo.nl/en/webshop/acce...tamp-hinges/In fact, I just located my hinge test pages which included nearly 30 tests of hinges, but a few are duplicate tests. I see that beneath the line labeled "Davo hinges/red packet" are a dozen pretty heavy hinge remnants followed by what I wrote about them, the single word "Awful". So at the time, it was my impression that Davo hinges were clearly not an option for me and must be sourced from the same company as all the others -- which I now know is likely to be Prinz.
I also see that I also tested Davo hinges on another album page, so testing them a second time. The note next to those Davo hinge remnants is "left more hinge remnants," meaning "more" than the other hinges I tested.
So in my test, in any case, they were no better, and perhaps worse, than other brands of hinges. Of course, this could have been the result of being wetted more than the others, though I tried to be very careful not to do that. Needless to say, all modern hinges that are currently sold failed my test pretty miserably. All left big hinge remnants behind and would surely damage a stamp unless the hinge were left on the stamp, and who wants that?
But I'll try Davo again based on hy-brasil's comments just to compare them. Maybe Davo has changed their hinges? I know Davo also sells the only non-lickable stamp mounts available (at a fairly expensive price), but mounts are not the same as hinges, of course.