All The Internal Parts Needed To Complete A Smooth-Functioning, Reliable Lower Complete kit of all the internal parts, plus the pistol grip, allows you to build or refurbish on the small-pin lower of your choice. Unified set of components designed to work together helps ensure proper fit and smooth operation. Engagement surfaces on trigger and hammer are precision ground to give you a crisp letoff without sacrificing reliability. Pistol grip is injection molded from high-impact polymer and offers the streamlined contours of a standard A2-style grip, with a ledge for the second finger, molded in checkering, and deep grooves on the backstrap for improved control under recoil. Separate triggerguard molded from the same high-density polymer is included.