These are custom Machined rings only 4 sets were made. They are 303 stainless. For 34 mm scopes. They are .990 from the bottom of the ring to the center of it. Overall length is 1.260" and the clamping area is .800". Ring cap screws are 10x32 screws. Base screws are 6x48. The 6x48 screws are long and will need to be cut down a little bit to get the proper length. There is also a dowel pin hole on the underside of the rings to have them pinned, it isn't a through hole. They are for stiller predator actions or others that require the same mounts as the predators. I believe the base screw spacing is .860" and the bottom of the ring is machined for an action diameter of 1.350". They are $250.00 shipped. Thanks