These high-quality parts are manufactured to precise tolerances in accordance with MIL-STD 105D to ensure correct fit in a mil-spec receiver. Includes complete trigger/hammer group with precision-ground engagement surfaces for a smooth, clean trigger pull and crisp release. Aluminum trigger guard with pre-installed detent pin resists impact and won't crack in cold weather. High-impact polymer pistol grip is original A2 style with single finger groove on the front, vertical serrations on the backstrap, and checkered panels on the sides. Add the receiver extension/buttstock system of your choice, and your rifle's bottom half is complete.