The Standard Picatinny Rail Forearm fits 2.3-inch for 410/45colt and fits 1.9-inch for 300blkout/5.56 rail sizes and Full Length Picatinny Rail Forearm fits 3.4-inch rail for 410/45colt and fits 2.8-inch rail for 300blk out/5.56 sizes for lasers, flashlights and grips accessories. It requires the factory screw that comes with the gun. Then for the Riot Grip, you can use the screw, lock washer and washer that comes included. Included with a rubber hand grip for Riot Grip. There are two different models for the brawler 410/45 colt. Then the 300 blk out and 5.56 they are the same forearm and fit the same. There is no firearm included or regulated parts. Please contact me if you have any questions.
