I have them. They are the best quality possible. You have to look hard to see where one piece of steel ends and the other begins. Installation is not easy; these things are machined so precisely, that you almost have to have and use allignment rods to put the scope up properly. They do come with a tool and installation instructions, you could do the installation yourself; however, these mounts and rings are so precisely machined that you would not get the full potential from them if you do not instal them and allign them properly, and if you do not level the scope. I had a qualified 'smith install mine (he also lapped the rings slightly), especially since they were put on nice rifles and held expensive scopes.