The CMC Triggers Customizable Lower Receiver Parts Kit is a great addition to your AR15 build. From the amateur gun builder to the seasoned expert gunsmith, this lower parts kit is perfect for a custom build project. Add a drop-in trigger and pistol grip of your choice to complete your build without leftover parts you don't need or want!Kit IncludesBolt CatchBolt Catch PlungerBolt Catch SpringBolt Catch Roll PinMag ReleaseMag Release ButtonMag Release SpringBuffer Retainer SpringSafetyBuffer RetainerSafety Detent SpringSafety DetentTrigger GuardTrigger Guard Roll PinTakedown Detent SpringsTakedown DetentsTakedown Pins