The M4E1 PRO Lower Receiver seamlessly integrates ambidextrous controls into the M4E1 Lower that allows for the shooter to easily operate the bolt catch, magazine release, and safety without modifying their dominant firing hand. Platform: M4E1 Compatibility: Works with M4E1 and AR15 components and magazines INCLUDES: M4E1 PRO Lower Receiver PRO Ambidextrous Safety EZ Takedown/Pivot Pins Aero Precision Enhanced Buffer Tube H Buffer Magpul MOE Grip Magpul MOE SL Stock Mfg: Aero Precision