Not something you see often: Élysée Sachs - Huret rear derailleur

Just rolled in. Took me a while to figure out how this thing actually works. Turns out it uses a flexible steel rod rather than a regular gear cable to shift between the gears. There is no L and H adjustment screws.

Reminded me there is whole era of shifting products before SIS has been introduced which most of us take as an obvious thing that has always been.