20" Govt profile bbl, YHM flip up front sight, Briley carbon FF tube with YHM 3" rails installed at 3/9 o clock, Postban Smith muzzle brake (set screw), and sling swivel stud at 6 o clock. This upper has fired sub MOA 300 yard groups and the bbl is fairly low round count (under 2K). It was originally a factory Bushy M4 upper that I had a 20" tube installed on. It shoots great but I'm not using it anymore, it's just sitting in the safe. This is my "poor man's SPR" upper. I figure to have about $775 in it. Will sell for $500 shipped. Thanks for looking.