Felix Arithmometer - Francis WEB

FELIX is a brand from USSR (the old Russian federation). If you want to know the full history, perform a WEB search with the keywords: IRON FELIX.
You will certainly find a lot of articles about Felix Dzerzhinsky, shown below

The strange thing is that Felix was not a scientific, or an inventor. He was a politician, and ended up in the soviet secret police. So what's the relation with a calculating machine?
In 1924, he saw the Odhner Calculator and decided that Russia should have a similar device. So he simply copied all the design, making a few changes to be cheaper and easier to produce. And the FELIX Arithmometer was born:

This machine is using toothwheels, and has the same operation principle as the Odhner. You select the number using the dials on the top, and the number of turns of the crank on the right will be the number of times you add these numbers.
On the front, the small black selector allow you to move the carriage to use power of 10. So you can quickly multiply a number by 20, by doing 2 turns of the crank when the carriage has been moved one slot. And so on, up to the 8 possible moves.

According to some users, the Odhner is better build and has a more robust construction. But keep in mind that the Felix was designed to be cheaper and easily built.

The one I bought came directly from Ukraine and is still working pretty well.

Below is a video to explain the basics of operation, for addition and multiplication.