It does just what it's supposed to - Leapers UTG Sub-Compact Rear Sight for Shotguns, .22 Rifles

I have several of these sights installed on air rifles.
They are set up for a weaver or picatinny rail, so one needs a converter from the dovetail slots on most guns, but those converters are cheap. (I order mine from China and they're a dollar or two each.)
It has excellent windage and elevation adjustment, although the elevation adjustment is somewhat restricted.
It's simple to install and simple to adjust. It's well built and light enough that it doesn't move due to recoil.
Couldn't ask for more.

Peter