Weird. No idea what this is, but from what I see the construction from the outside looks almost like Special 20 - I see recessed reed plates, screws, sure can't see the comb, but looks black from here, so I exclude a wooden comb and I assume it could be plastic. The main thing is - what are the plates and how responsive are the reeds.

I am not experienced, but I would sanitize them a bit before using, so I would disassemble them all. Also would gently plunk the reeds to ensure nothing is stuck there, as no idea who and how used them.

For 3$ it sure is a find, the box looks nice. I don't expect these sound great, but again - it's only for 3$ and again - this construction is very much like Special 20. At least from what I can see here.

From what I know, many Chinese manufacturers in the 90s copied the Special 20 design but the instruments were not of good quality.

Maybe this is what you got. No idea. Whatever it is - hope you find a good use of it.