Base screws are 8-40 X 1/4 long. Ring screws are 6-40 X 5/8" long. Base screws use a 9/64 Allen wrench. Ring screws use a 7/64" Allen wrench. Outside to outside of rings is 3.92". Standard rings are .63" wide and have 2 screws per ring. (4) hole to hole spacing dimensions are .86, 1.27, .86. Height of mounts from top of barrel to centerline of scope tube is medium 1.13". This product is precision machined from a solid block of top-grade billet aluminum, absorbs shock, and withstands temperature extremes better than steel mounts at a fraction of the weight.
Determined at checkout.