The Aero Precision LR-308 M5 Upper Receiver Assembly is designed with size and weight in mind, while still providing plenty of real-estate to accommodate any attachment needs the end user may have. The proprietary ATLAS attachment system is a durable and dependable mounting platform, maintaining a slim profile while still providing the strength and stability customers have grown to love from Aero Precision handguards. FeaturesForged from 7075 T6 aluminumM4 Feedramps.2795 takedown pin holesLaser engraved T-marks (Anodized Only)DPMS High Profile (.210) Tang)Includes port door and forward assist