Use with Standard (STD) rings. Detachable scope mounts guarantee that you'll return to zero without fail. The forward part of the base accepts a dovetail style ring, locking it solidly into position, while the rear ring is secured by windage adjustment screws. 2-piece bases are fluted for a customized look, offer greater flexibility in mounting options, and fit both left- and right-hand action rifles. Reversible bases accommodate a variety of scopes and action lengths. Made in USA.