Since I had the rail, I felt like adding some rings. There are two sets of rings, a ~25mm size with two sets of machine screws, and a longer, ~35mm set with three sets of machine screws. I test fired these with my Hatsan 125 air rifle and it held up. I haven't gotten the check how well these will hold a zero yet. My first set seemed a little off centerline when I dropped the scope in, which is why I made the second, longer rings. Update 1/21/15: I print the rings laying down cross-wise and the cleat from the side. I used 6-32 machine screws for securing the top of the ring the base. The square rod with the threaded end, I have no idea what it is. If you know, leave a comment, I salvaged it from an old red dot scope I had laying around. With that being said, a long thin machine screw and wing nut could to the same thing.