I modified these on my milling machine to fit on my R22 (sold it, kept the sights) They are factory HK SL8 Iron sights. Here are a few pics on the gun.
They slide on the rail form front or back. You can put both screws in the rear sight even though only the one goes in a groove. Only one screw lines up with a groove on the front...the grooves in the top rail are spaced different, you could mill/file a new grove if you feel it necessary...it isn't going anywhere.
When you install the screw (that line up in grooves) they do mark the top of the rail as they screw in because they rub the groove. The rear screw rubs more than the front one does...not a big deal for me, but may be for others.
I installed them, but never fired the gun with them installed.
They were purchased as slightly used and they are as new condition, but the screw heads finish on a couple screws is kinda blemished looking......long ass story, huh
For those not familiar with SL8 sights..they are mostly plastic, the rear sight is a flip "L" style with different sized/ranged peeps. It is adjustable for windage and elevation.
I can take more specific pics of the sights if you need.......$50 shipped! Paypal or MO
I actually prefer Paypal...so no added fee.
E-mail me email@example.com