Howdy y'all, I found this last Saturday, I saw it said USAF and thought that it as a pretty cool item. One is stamped with a "S" on the brass fitting and the other is not. From what I have found it appears to me made sometime in the 1950's. The person I got it from used to refill fire extinguisher's. Both still have some kind of hellish liquid in them, although only one can still squirt out the liquid. I use the term ""hellish" Because the one that works accidently went off on me. I can say from experience that it burns, (but does not scar your skin), makes your nose and eyes water and makes you keep coughing for a long time. But one pro is it makes for one heck of a ant spry. I just though that it looked pretty cool.