I was watching a video that featured a Negimaru 120 and it has a really interesting drive(?). It’s a vegetable slicer

Here’s a video, a review maybe? It’s in Japanese but that’s not necessarily important… here’s two timestamped links. The first one shows being able to plug into different gears to adjust the thickness of the cut. The second one has a great closeup of it working

https://youtu.be/U8k9ISBPPQw?t=210
https://youtu.be/U8k9ISBPPQw?t=247

Using auto translate, it came up with “joint wire” that led me nowhere. I know it’s basically like a flexible drill extension, but what is that action actually technically called?