ᐅ Side showers inside the shower enclosure. Does anyone know this model?

Hello,
Last winter, we bought a house that is 13 years old.
The shower was renovated a few years ago, probably around 8 years old judging by the silicone. It has been patched twice instead of being completely redone, but that’s not the main issue…

My concern is with the side jets installed in the shower. Water now only comes out of the inner holes. The “ring” seems heavily scaled.
The jets are secured only with an Allen screw, and I soaked each one fully in vinegar for 24 hours with ultrasonic assistance. Unfortunately, there was no improvement.
Do the jets need to be completely disassembled before cleaning? If so, how?
Is it possible to get replacement jets that fit on the brass flange in or on the wall?
What is the model or manufacturer called? Unfortunately, my Google searches were unsuccessful.
Removing the wall to install a new system is not an option for now.

Thanks and best regards,
Sebastian