I designed this AR grip adapter to fill a void in the market. At one time there were quite a few decent options out there, but those have all but disappeared. I designed this from the grip up with simplicity, affordability, and compatibility in mind. It is made from PA12 Nylon using cutting edge Formlabs Selective Laser Sintering machines right here in the USA. It is bead blasted and dyed for a textured satin black finish. The pin and safety holes are drilled and precision reamed for a solid installation and smooth operation. The only thing that may require a little fitting is the surfaces that constrain the trigger and sear. I made them a tad on the tight side to ensure that they work for the most amount of folks. If it's too tight you may need to either file the inside of the grip adapter or file the adjacent surfaces on the trigger and sear. We have 8 13XX and 2240s and tested these on them without the need to file on all, but one. We kept many of the dimensions close to the original OEM grip frame so as to maximize compatibility with all the mods currently on the market. It comes with everything you need and you'll reuse the original trigger, sear, pins, and safety parts. It comes with a lighter spring that replaces the OEM sear spring and replacement allen head screws. It is compatible with our AR stock adapters, rear pic adapters, and Plumper Pumper. It is also compatible with power adjusters.