DNZ Products Game Reaper- Ruger® American 30mm SA Mount Ruger® American (centerfire): Mount fits both left and right hand firearms. Base screws are 6-48 X 1/4? long. Ring screws are 6-40 X 5/8? long. Both screws use a 7/64? Allen wrench. Short action – Outside to outside of rings is 3.97?. Standard rings are .63? wide and have 2 ring screws per ring. 4 Hole to hole spacing dimensions are .86?, 3.01?, .86?. Height of mounts from top of receiver to centerline of scope tube is - low .92?, medium 1.05?, and high 1.17?. Specifications: - Precision machined from a solid block of top-grade billet aluminum - Custom made to fit each type of firearm and align perfectly with your rifle’s receiver - No moving parts between the firearm and the scope - 67% lighter than comparable one-piece mounts with four times the threads and precision socket-head cap screws for absolute strength and security - Absorbs shock and withstands temperature extremes better than steel mounts at a fraction of the weight - Made in the USA Manufacturer: DNZ Products MFG Number: 16280 UPC: 879956006011