if it says us it is a military can opener out of c-rations or the older k- rations, K-rations are from ww2 and korea and c's are from vietnam into the 80's, to this day i still carry one on my keys
Excuse me, but I think jayhastings is wrong...I've used and seen many p38s. They have a piece that flips up. This seems to be one solid piece. The gentleman before mentioned it was from one of the later wars. I believe that he is correct.