Luth-AR Upper, Black, 1913 Rail for Mounting Optics and Accessories, Forged, Flat Top, Comes with Charging Handle, Forward Assist, and Dust Cover FTT-EA1 Start your new build with a Luth-AR .223/5.56 A3 Flattop Upper Receiver comes fully assembled with an M4-type feed ramp" 12 position Picatinny accessory rail for mounting scopes or flip-up sights. Shell deflector" forward assist" and ejection port cover. Precision machined from a 7075-T6 aluminum forging and hardcoat anodized for a tough" scratch-resistant coating.