Anybody know what this is?

[Sharpienads]

Looks like it clamps to either a barel or a gas tube...

Thanks for kicking in the OCD by the way, now I have to know what the hell that thing is.

Dude, I wish I knew, too. It's been sitting on my kitchen counter for the last week and I can't figure it out.

Maybe this will help: I was thinking maybe it attaches to the bottom of the barrel, as opposed to the top and the thing sticking out that looks like a gas tube (but isn't) rests in between the teeth of the barrel nut. There's a small, circular mark in the paint on the rail that is the same size as the locking mechanism for a KAC vertical grip.