Product DescriptionThe Aero Precision M4E1 Threaded Upper Receiver is built for AR-15 platforms chambered in 5.56x45mm NATO and is designed to stand apart from standard mil-spec upper receivers with its angular machined profile. Forged from durable 7075-T6 aluminum and finished in black anodizing, this stripped upper receiver is precision machined to work with all mil-spec AR-15 parts. It is threaded to accept a standard AR-15 barrel nut and features a Picatinny top profile, M4 feed ramps, and .250 takedown pin holes for dependable compatibility and performance. This receiver is an excellent foundation for a custom rifle build, but additional components are required to complete the assembly.Product Highlights Forged 7075-T6 aluminum construction offers strength, durability, and lightweight performance for AR-15 builds. M4E1 threaded upper receiver accepts a standard AR-15 barrel nut for broad parts compatibility. Angular machined design gives this upper receiver a distinctive look compared to standard mil-spec receivers. Includes a Picatinny top rail profile, M4 feed ramps, and .250 takedown pin holes for functional integration. Black anodized finish helps resist wear while delivering a clean, tactical appearance. Specs Brand: Aero Precision Manufacturer Part Number: APAR700201C UPC: 815421023756 Model: M4E1 Series: Threaded Receiver Product Type: Stripped Upper Receiver Caliber: 5.56x45mm NATO Material: 7075-T6 Aluminum Finish: Black Anodized Firearm Fit: AR-15 Rail Profile: Picatinny Feed Ramps: M4 Takedown Pin Holes: .250 Additional Components Required: Dust cover, forward assist, charging handle, barrel, handguard, gas block, muzzle device, gas tube, and BCG (Bolt Carrier Group) 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.