@futurebird most of them I have seen are simply a 50cm ruler of thicker metal (about 3-5mm) with a tassel on the end.

I suppose you *could* use it as some kind of ninja weapon if you wanted, but I suspect the Chinese are having a good laugh at the expense of American bros - especially for those rulers which have had the extra bits added (which makes them less useful as the handle won't lie flat) and are sold at premium prices - you can get the basic ruler for £10 and to be fair that does seem a bit more practical as an actual ruler.

Maybe it will even encourage Americans to use metric more😁