Aero Precision M4E1 AR-15 Receiver Set OD Green

The Aero Precision M4E1 Threaded Receiver Assembly Set includes the M4E1 Lower Receiver and the M4E1 Threaded Assembled Upper Receiver.M4E1 Lower Receiver FeaturesThreaded Bolt Catch Roll Pin - Allows for simple installation of the bolt catch and virtually eliminates the chance to damage the finish during installation (pin included).Integrated Trigger Guard - Eliminates the possibility of breaking the trigger guard tabs by integrating the trigger guard into the lower, creating a stronger more r