When mounted it works fine. The levers to tighten the mount rattle. The first time I took the scope off the rifle the piece of metal that fits into the rifle's Weaver slots fell out. It was really fun trying to put the scope back on the rifle holding it upside down. These are going back to Leupold. Stick with the Mark 4 rings.
Pros: Solid when mounted (just don't take them off).
Cons: The rail is a seperate peice of metal that falls out. The levers rattle.
This review was written in the old system and had content requirements that are different than reviews written today.