Product DescriptionThe Aero Precision M5E1 Enhanced Upper Receiver is built as a streamlined, high-strength foundation for .308 Win / AR-10 style builds on the M5 platform. Machined from 7075-T6 aluminum and finished in Flat Dark Earth Cerakote, this upper uses a one-piece design that integrates the handguard mounting platform directly into the receiver. This engineering reduces the number of parts required to mount a free-floated handguard to just 8 screws while maintaining a strong, clean, and efficient assembly system.This assembled upper receiver includes a port door and forward assist already installed, along with practical performance features such as M4 feedramps, .2795 takedown pin holes, and laser engraved T-marks for easier accessory alignment. The M5E1 Upper Receiver is specifically designed for use with Aero Precision M5 Enhanced Handguards and is not compatible with other AR10/.308 handguards. Additional components such as a charging handle, barrel, handguard, gas block, muzzle device, gas tube, and bolt carrier group are required to complete the build.Product Highlights One-piece enhanced upper receiver design integrates the handguard mounting platform for strength and simplified installation. Constructed from durable 7075-T6 aluminum with a Flat Dark Earth Cerakote finish for lasting performance and corrosion resistance. Includes forward assist and port door pre-installed for a more convenient semi-complete setup. Features M4 feedramps, .2795 takedown pin holes, and laser engraved T-marks for function and accessory indexing. Designed specifically for Aero Precision M5 Enhanced Handguards on the M5 platform. Specs Brand: Aero Precision Model: M5E1 Enhanced Upper Receiver MPN: APAR308506AC UPC: 815421021769 Caliber: .308 Win Platform: M5 Type: Semi-Complete Upper Receiver Material: 7075-T6 Aluminum Finish: Flat Dark Earth Cerakote Features: M4 Feedramps, .2795 takedown pin holes, laser engraved T-marks Included Components: Port door installed, forward assist installed Compatibility: Aero Precision M5 Enhanced Handguards Optics/Sights: None, optic ready 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.