Our Ultralight 30mm SPR Scope Mount features a rear ring that is pushed forward 2 resulting in better eye relief. This scope mount is designed to fit AR type upper receivers with Mil-Spec 1913 Picatinny rails and features a cross-slot keyway that offers excellent recoil protection. – Our Ultralight Scope Mounts free you from unnecessary bulk providing one of the lightest mounts in the industry. – Finish Anodized Black – Material 6061 T6 extruded aluminum construction – Scope Ring Size 30mm – Scope Mount Profile SPR – Weight(s) 3.36oz – Other Features Designed for AR type upper receivers – Ring/Base Torque: 15 in/lbs. Non-permanent thread locker recommended.