The American Defense Recon Quick-Release Scope Mount is made for putting high power glass onto a flattop style AR-15. The cantilever places the scope forward, allowing you to get the right eye relief. It is precision machined from 6061 T6 aluminum and finished in hard coat T3 Mil-Spec anodize. It features the patent pending Auto Lock Lever system to accommodate both in spec and out of spec rail systems. Additional Specifications:A) Height (top of rail to centerline of scope tube):1" Tube- 1.38"30mm Tube- 1.47"34mm Tube- 1.55"35mm Tube- 1.57"B) Length (Outside of forward ring to outside of rear ring): 4.48"C) Length (Inside of forward ring to Inside of rear ring): 2.52"D) Length (Back of mount to back of rear ring): 1.45"E) Length (Front of mount to front of forward ring): 1.93"F) Ring Width: 0.98"