A KM#X number is a fancy way to say X#, which is to say, it's in Krause's Unusual World Coins catalog.
This doesn't really mean anything regarding its quality as a coin - that catalog has everything from fantasy coins of real countries to Shire Post Mint stuff (coins of fictional countries) to micronationals (including circulating issues) to, IIRC, the occasional actual obscure coin.
The
NGC page mentions "formerly KM#M6", which presumably means it's a medal (or at least used to be considered one).