Aero Precision has everything you need here to complete your stripped lower. All mil-spec made in America. If you want detail it has: Takedown/pivot Spring
Takedown/pivot detent
Trigger/hammer pin
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
Trigger guard
Trigger guard roll pin
Magpul MOE SL (slim) Grip (my favorite)
Pistol grip screw
Pistol grip lock washer
Trigger spring
Hammer spring
Disconnector spring
Magazine catch body
Magazine catch spring
Magazine catch button
Hammer
Trigger
Disconnector