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 Specifications: Weight: 2.8oz Center Scope Height: 1.45" Base Clamp Screws: 45-50"/ lbs Ring Screws: 15-18"/ lbs Included in the Box 2 Precision Matched Rings Torx Wrench