Aero Precision APRH101327: Aero Precision\'s EPC Lower Receivers include the proprietary parts pre-installed from the factory. Other parts and components for assembling your lower receiver are standard AR15 compatible parts. Aero Precision\'s EPC Lower Parts Kits include just the parts you need for assembling your EPC Lower Receiver and nothing else. Aero Precision\'s line of Lower Parts Kits available with included Magpul Grips give you the flexibility to purchase your lower parts kit with the grip that best suits the needs of your build. Includes: Takedown/pivot Spring Takedown/pivot detent Takedown pin Pivot pin Bolt Catch Bolt Catch Spring Bolt Catch buffer Bolt catch roll pin Safety Selector Safety Selector spring Safety Selector detent 4-40 Set Screw (for threaded takedown pin detent hole) Buffer retainer Buffer retainer spring Magpul MOE grip Pistol grip screw