I'm not sure of the manufacturer, as there are no markings anywhere on it that I've seen, but it's ran flawlessly for me. I bought it used from someone else, and since I've had it, I've put 360 rounds through it. Never skipped a beat. Finish all over is in great shape. I can get better pictures if needed. $375 shipped.
Note : Upper receiver only for sale.
ETA : No barrel markings either. Small hole upper. Also, the handguards have some side to side play in them, but if you put on a different set, such as a bushmaster set of CAR handguards, the side to side play is gone.