I’m selling a super stubby M4 setup perfect for all the speedy guys out there. Includes inner barrel, outer barrel, barrel nut, and handguard. The inner barrel sticks out a little bit, but a tracer can still be used. Yes, it will fit on your Super Duper Shooter Matrix Polarstar ARP349 DMR with integrated sight. If it’s an M4 upper receiver, it’ll fit. $40 OBO + shipping ALL SALES ARE FINAL NO REFUNDS/RETURNS