The Geissele Standard AR-15 Lower Parts Kit includes all the internal parts necessary to complete or rebuild your lower receiver. This quality mil-spec kit features an improved safety detent and our specially designed Posi-Snap safety, which provides the end user a satisfying and positive tactile feedback when engaging the safe or fire position. FeaturesTakedown Pin & Pivot Pin Detents (2) Takedown Pin & Pivot Pin Springs (2)Takedown Pivot Pin Bolt Catch PlungerBolt Catch Spring Bolt Catch Coiled PinSafety Detent Mil-Spec Bolt CatchBuffer Retainer Buffer Retainer SpringSafety Detent Spring Takedown PinMagazine Release Spring Magazine Release ButtonPosi-Snap Safety Magazine CatchCoiled Trigger Guard Pin Mil-Spec Trigger Guard