Product Description The Aero Precision M4E1 Threaded Assembled Upper Receiver in Kodiak Brown Anodized finish delivers a distinctive billet-style aesthetic at a fraction of the cost of a true billet receiver. Forged from mil-spec 7075-T6 aluminum and precision machined to accept all standard AR15/M16 components, this upper features a bold angular machined design that sets it apart from ordinary mil-spec uppers. Its threaded barrel extension accepts any standard AR15 barrel nut, and it ships fully assembled with both the port door and forward assist pre-installed. The seamless Picatinny rail profile integrates perfectly with Aero Precision&';s Enhanced and ATLAS Series handguards for a clean, unified build. Whether you are upgrading an existing rifle or starting a new build, the M4E1 pairs perfectly with Aero Precision&';s M4E1 Lower Receiver for a matched, modern look. Product Highlights Kodiak Brown Anodized Finish: Eye-catching warm brown anodized coating provides a distinctive look while offering durable corrosion resistance. Billet-Look Enhanced Forging: New angular machined design gives the upper a premium billet appearance at a forged price point, forged from 7075-T6 aluminum. Seamless Picatinny Rail Integration: Picatinny profile blends seamlessly with Aero Precision&';s Enhanced and ATLAS Series handguards for a streamlined, professional build. Fully Assembled and Mil-Spec Compatible: Ships with port door and forward assist pre-installed; compatible with all standard mil-spec AR15 components and standard AR15 barrel nuts. Made in the USA: Precision machined in the United States with laser-engraved T-marks, .250" takedown pin holes, and M4 feed ramps for reliable performance. Specs Brand: Aero Precision MPN: APAR700222AC UPC: 840014618354 Material: 7075-T6 Forged Aluminum Finish: Kodiak Brown Anodized Platform: AR-15 Weight: 8.65 oz Takedown Pin Holes: .250" Barrel Nut Compatibility: Standard AR15 barrel nut Barrel Nut Torque: 50 ft-lbs Feed Ramps: M4 T-Marks: Laser engraved Includes: Threaded forward assist roll pin, port door and forward assist (pre-installed) Country of Manufacture: USA Item Condition: Factory New Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer. ]]>