The next example is not only puzzling, it looks like a puzzle. In fact, it is a rotating 5-franc calendar piece issued by Congo. The very thing it is designed to be clear about, the date, is also what makes it confusing. This coin has no date of mintage on it. It was issued in 2004 with a calendar that can determine dates between 1995 and 2044, thus the 50-year calendar would be useful for only 40 years from its time of issue.
The second Congolese coin is a 10-franc piece from 2007 made of plastic. A coin made entirely of clear acrylic is not necessarily a bad idea. But this one is 50 millimeters in diameter and 20 millimeters thick, so it does not fit any standard storage system. It doesn’t come with a custom capsule either.
But it is the subject that makes it truly odd. You won't find an African theme here.
This coin honors a Dutch admiral, Michiel de Ruyter (1607 to 1676). Nothing in history, previous to this coin, links Congo to Adm. de Ruyter or his native land.