TPS Arms AR-15 Lower Parts Kit Features: 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. TPS Arms AR-15 Lower Parts Kit Specifications: All parts are manufactured in the USA. 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