I sell a lot of things I don't know a lot about in advance and this is one of them. This came to me in a group of effects from a deceased US Navy SEAL who like many military people accumulated some keepsakes and souvenirs along the way. Likely exchanging such items with those he worked with on overseas missions. Apparently he was in the United Arab Emirates and this may have come from there. He was in SEAL Team Four from Little Creek if that helps. Name given to buyer on request. Very Good condition, seems used but not damaged. Have no idea how to size this but I wear a 7 1/2 baseball cap and this fits me nicely down to the ears. Of some but uncertain vintage, if we have an office pool on it I will take eighties or nineties but again it is not anything I know much about, I am basing it on the time the late veteran served.