I got this with a set of original 80s/early 90s production BDUs in the same camo.  Seems to have not been worn.  No label/tag of any sort, no idea on official size or who made it, but it's made of original old fabric, the same you see in the commonly issued desert night parkas.

I wear a 59cm issue beret, this fits me very snugly.  Sits very deep on the head unlike a standard cap.

All my other sale items are viewable here:

https://flic.kr/s/aHsjPXJkHw