This is a after market scope mount for the Pre Ranch (early) models of the Ruger Mini14. This scope mount is made of an anodized aluminum alloy and has multiple adjustment points to ensure stability and a repeatable zero. Why is it so cheap you ask....good question... UNFORTUNATELY I no longer have the threaded bolt hold open plate that this scope mount screws into. If you have a Mini14 that has a threaded bolt hold open plate installed, your good to go. If you want to drill and tap the existing plate on your rifle, again you'll be good to go. If for some reason you have the plate but not the mount, again your good to go. The threaded bolt hold open is necessary to utilize this mount. Thanks for looking.