This is an original FB Radom Beryl Right Night sight set piece for the Beryl Rifle or can be fitted to the WZ-88 Tantal Rifle.
these pieces are quite commonly found on the military firearms in Poland. The reason being behind the night sights for the Tantal and Beryl rifle was not only for Night shooting but also used to help the end user with poor eye sight for military iron sight qualifications and for better target accusation on the battlefield, if running on irons only.

This would be a perfect peace for anybody's Polish military collection if they are building a Tantal WZ-88 or Beryl WZ-98 Rifle clone.

if you have any questions, feel free to reach out!