Arken Optics Rigid Precision Cantilever Mount 0 MOA 30mm. 5 Inches of forward extension for better eye relief typically desired for use on AR style platforms. The Rigid Precision mounts are fully CNC machined from aircraft grade Aluminum resulting in the highest precision and tolerances possible. Arken Optics recommends max torque settings no greater than 18in/lb for ring screws and 30in/lbs for base screws. The optic manufacturer's specification shall always supersede Arken's Halo Rings specification unless higher. Specifications for Arken Optics Rigid Precision Cantilever Mount: Manufacturer: Arken Optics Fabric/Material: Aircraft Aluminum Color: Black Base/Mount Type: Cantilever Ring Mount Gun Model: AR-15 Package Contents: Arken Optics Rigid Precision Cantilever Mount Arken Optics ARP-30Z: Rigid Precision Cantilever Mount 0 MOA 30mm