Double hex screws to hold your scope firmly in place. Weaver version features crossbar for additional security. Internal cushion tape prevents marking and damage. High-grade aluminium anodized in matte black Configuration: 2 Piece Ring Size (Diameter): 30mm Height: Low Rail: Weaver Fixings (Rail & Top Cap): Double Hex Screw Internal Cushion: YES Retractable 'Recoil Stop' Pin: No Height: 44mm / 1.7 Weight: 84g / 3oz