I have a few of these. There was a cheaper source earlier for EUR 4,00 each.
They are strongman 1 grey switches or Xm switches. Both feel terrible.
Keycaps are pad printed and lose their letters about 2 month in.
Switches are plate mounted on a plastic plate that flexes and bends like crazy.
Stabilizers are terribly cheap and flex too. Backspace, Shift don't even have stabilizers so you have to hit them in the dead center.
Overall this is a terrible keyboard.