These are unused hat crests from old surplus but please note they are cheap to begin with and some bag wear must be expected. Probably made in the Soviet Union, either way the Vietnamese vagaries were never top quality. Screwback with retaining nut. Sold in pairs. Used on the green Pith Helmets which were also used by their Army. The same hat with a Navy crest instead of an Army one is worth a good ten dollars more. Possibly wartime but more likely post-Vietnam war era but so far as I know they are basically the same thing. Multiple pairs were at least at the start available so you may or may not get the ones in the photos but they are all the same.