Machined with certified USA 7075 T6 billet aluminum and held to an extremely tight tolerance of .0005 inches using a precision Computer Numeric Controlled (CNC) mill. These Vortex rings are then serialized, vibratory tumbled, bead blasted and finished with a Type III hard coat anodize. Rugged, lightweight, anti snag design. Robust, Grade 8 fasteners. 100 made in USA guaranteed for life. Will work with Weaver and Picatinny mounts