Our M4A1 Clone Complete Lower Receiver features custom engraving on our AR15 Gen 2 Lower Receiver and is the perfect complete lower for your M4A1 clone build. – Includes: – M4A1 Clone Lower Receiver – Standard Collapsible Stock – Standard A2 Grip – Lower parts kit – Receiver extension – Carbine buffer kit – These parts are installed – M4A1 Lower Receiver Features: – Custom Aero Precision logo – Markings include: Property of U.S.A. MOD M4 CARBINE CAL. 5.56MM – Serial number designation – Safe/Semi/Auto safety selector markings – Gen 2 Lower Receiver Features: – Upper Tension Screw- Allows users to fine tune the fit of the upper and lower receiver through the use of a nylon tipped tensioning set screw inserted in the grip tang of the lower receiver. This provides a tight fit with any standard AR15 upper receiver. – Increased Magwell Flare- Allows for easier insertion of magazines and provides a sleeker look.