High-strength aluminum Alloy ring, with integral rail, clamps to any 30mm diameter scope so you can mount flashlights, lasers, nightvision and other accessories to your favorite tactical arms. C.O.R.A. I features a single rail that accepts Mil-STD 1913 (Picatinny) and Weaver-style mounts. Four, Torx screws tighten the ring halves for superior holding power. SPECS: 7075-T651 Aluminum Alloy, matte black, hard anodized to Mil-A-8625 standards. 5/8″ (15.8mm) wide. 3/8″ (9.5mm) high from top of scope tube to bottom of rail. Accepts Weaver-style or Mil-STD 1913 (Picatinny) mounts.