4140 Heat Treated Barrel Nut – Barrel Nut and Wrench Included – Features Patented 4140 Heat Treated Torque Plate – 7 overall length – 6.8 oz Installed Weight – 6061 Aluminum Type 3 Hard Coat Anodized – Continuous MIL-STD 1913 Picatinny Top rail – Two Integral Anti-Rotation QD Sling Sockets – Super Slim 1.5” Outside and 1.3” Inside Diameter – Seven Sides of M-Lok – 5-Slot Polymer M-Lok rail included – Fully Dehorned and Deburred – 100% Made in USA- Keeps America Working – MI Lifetime Warranty