Slim-profile, compact rail system with extended top rail to allow mounting of optics and accessories. Top rail is in line with the upper receiver rail, and extends back over the delta ring to allow mounting of optics across the entire top of weapon. Issued to Israeli Special Forces, Duvdevan, and Yamam. The NFR rail system firmly locks to the barrel nut so mounted optics retain zero. 6" long. Drop-in installation. CNC machined hardcoated black anodized aviation-grade 6061 T6 aluminum. See also NFR-M5 for mid-length AR weapon systems See also NFR-RL for rifle length AR weapon systems