Precision machined from a solid block of top-grade billet 6061T6 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 percent 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