I use Burris signature Zee rings on every thing, and decided to use then on my new 22lr. I have a bunch on guns and spares so I started looking for and adapter. Its a little spring loaded thing and came with a China return address and no instructions. It looks to me as if it compresses and goes inside the ring and when tightened the clamp screw on the ring compresses the ring and the adapter. But there is a small set screw that screws down from the top of the adapter. I have no idea what the set screw is for or how you would tighten it after the ring is in place. Any one ever use one of these, I bought it cause it would almost be invisible once installed. Thanks for your help!! mark