This 5.56 NATO AR-15 lower receiver parts kit is comprised of high-quality, Made-in-the-USA, mil-spec parts. Each part is packaged in color coded bag for easye in finding it for installation. This kit is an excellent choice for building or rebuilding an AR-15 rifle. Contains: takedown pin, receiver pivot pin, takedown pin detent (2), takedown pin detent spring (2), bolt catch, bolt catch plunger, bolt catch spring pin, bolt catch spring, buffer retainer, buffer retainer spring, magazine catch, magazine catch spring, magazine catch button, trigger guard assembly, triggerguard pivot spring pin, safety selector, selector detent, selector detent spring, grip screw washer, grip screw. Does not Mfg: Brownells