This rail mounts over the front OEM sling swivel, just remove stock rivets, mount original front sling swivel between rail and stock, fasten with washers and screws provided in kit. This 3 ½” rail is great for mounting a bipod, or other accessories. Not limited to the M1A / M14, this rail can be mounted on other weapons that have a need for a rail. Rail is manufactured to MIL-STD-1913. Machined from a solid billet of 6061-T6 Aluminum, and finished per Military Specification MIL-A-8625 Black Anodized finish.