Aero Precision Ar-15 M4e1 Assembled Upper Receiver 5.56mm

Aero Precision's M4E1 Threaded Assembled Upper Receiver gives you the best of two worlds: that badass looks and robustness of a billet receiver plus the easy parts compatibility (and price!) of a traditional mil-spec upper. And it comes with two nit-picky jobs done for you: the forward assist and ejection port cover are already installed. But there's more… The M4E1 Threaded Assembled Upper Receiver is Aero Precision's M4E1 Enhanced Upper with standard barrel threads up front so it can accept a standard AR-15 barrel nut and handguard attachment. The original M4E1 upper is configured for the proprietary attachment system Aero's Gen 2 Enhanced or Atlas 'g Mfg: Aero Precision