Last month, there was a sale on Colt 6921 uppers. Since I absolutely don’tr need any more AR uppers, I bought one anyways.
The Colt 6921 upper is a 14.5 inch government profile M4 upper. Your bog standard M4 upper. Not to be mistaken for the 6921HB or SOCOM model, which has a heavier profile barrel (.75 inch with M203 cuts).
It comes in a nice box, and it includes a Colt AR15 manual.
The sticker on the side shows that this is part number SP401165.
The upper comes in a bag that is designed to prevent rust. It also comes with a wick in the barrel.
This particular upper does not come with a charging handle or bolt carrier group. Also there is no side sling swivel included.

I wasn’t going to post about this plane jane upper, but then I remember there are those weirdos out there who care about stamps, marks, and the like. I figured I should post it up for reference. I received this upper from Brownells in Dec 2020.
Sometimes I read about someone getting a new upper and complaining that the finish is defective and grey on the inside. No, that is dry film lube.
The front of the upper receiver is M4 marked, but I was unable to get a clear picture of it.