This AR-15 lower parts kit includes everything needed to build a complete lower receiver assembly (excluding a pistol grip) using your existing stock assembly and lower receiver. All parts meet or exceed standard military specifications and are made in the U.S.A. - Our kit includes premium parts such as our Enhanced Trigger Group enhanced machined billet trigger guard and our premium billet machined magazine catch assembly. - All parts are manufactured in the USA. - Kit Contents: - Bolt catch - Bolt catch buffer - Bolt catch roll pin - Bolt catch spring - Buffer retainer pin - Buffer retainer spring - Disconnector - Disconnector spring - Hammer - Hammer pin - Hammer spring - Magazine catch - Magazine catch button - Magazine catch spring - Pistol grip lock washer - Pistol grip screw - Pivot pin - Pivot pin detent - Pivot pin detent spring - Selector - Selector detent - Selector spring - Takedown pin - Takedown pin detent - Takedown pin detent spring - Trigger - Trigger guard - Trigger guard roll pins (front and rear) - Trigger pin - Trigger spring