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. Features: Rugged, lightweight, anti-snag design Robust, Grade 8 fasteners 100% made in USA guaranteed for life Specifications: Center Scope Height 1.45 inches (36.8 mm) Weight (per ring) 80 grams (2.8 oz) Mount Compatibility Picatinny Base Clamp Screws 45-50 in/lbs Ring Screws 15-18 in/lbs Included in the Box: 2 Precision Matched Rings Torx wrench