This is a Williams made diopter/peep sight. It has been drilled and taped to fit a Weihrauch springer. Has the stop screw that fits the holes in the receiver of a Weihrauch. Screw is brass so it will not damage the receiver. Also the sight has a eye shade. It’s the new version of Williams in the matte black finish. Sight is new. $50. $5 shipping. Continental U.S Only. 