If you have a 10" or 16" barreled upper for your Mac or MPA in 9mm or .45 acp and want to add some accessories, then this is for you! It offers three picatinny polymer rails, one underneath for your choice of AR type slide on grip, and two rails on the upper sides of the hand guards for a laser and flashlight. Just remove your current AR hand guards and install our two piece set, tighten down the threaded cap and your gun is ready. Includes: two polymer hand guards with three polymer picatinny rails. (gun & other parts sold separately) Please call with any questions. Does not fit MPA Mini 930 pistol. **ONLY FITS NEWER MASTER PIECE ARMS type 10" & 16" barrels.