This lower parts kit from American Tactical is made from 100% durable nano composite technology and steel parts that fits and will complete your AR-15 stripped lower. Featuring the SAF-T-FIRST fire control group, this new design allows the firearm to be loaded with the safety engaged, drastically reducing accidental or negligent discharge of the firearm. American Tactical believes in safe firearm practices and the SAF-T-FIRST fire control group allows the firearm to be stored loaded with the safety engaged. The kit also includes the pistol grip, takedown/pivot pin, safety and bolt catch assemblies.