These look exactly like a set of cheap Chinese knockoffs that I have (I paid about $20 for two AND buttons).
Assuming that they are what I think they are, they are not high quality (they aren't Sanwas or Semeitsus) and the restrictor "plate" is a piece of soft plastic.
I bought mine knowing exactly what they were for a 2/3 scale JAMMA project for kids, but I wouldn't use them on a primary cab that would be used by adults.