The Schmid Tool Gun Nuts TF Two Stage AR-15 Lower Receiver Parts Kit was crafted by Schmid Tools, a company that has been producing fire control groups and lower parts kits for military contracts since 1980. Schmid Tool knows exactly what goes into making every part perfect. Includes:TriggerHammerDisconnectDisconnect SpringHammer SpringHammer PinTrigger SpringTrigger PinSafetySafety DetentSafety Detent SpringBolt CatchBolt Catch Roll PinBolt Catch PlungerBolt Catch Plunger SpringMag Catch AssemblyTrigger Guard AssemblyTrigger Guard Roll PinBuffer Retainer PinBuffer Retainer SpringPistol GripPistol Grip Screw And WasherTake Down PinTake Down DetentTake Down Detent SpringPivot PinPivot Pin DetentPivot Pin Detent Spring