XYN Calibration Cube, 20 mm

A simple 20 mm calibration cube without the "Z" on its top. Instead, it says "N", which stands for a ["Normal"](https://en.wikipedia.org/wiki/Normal_(geometry)).

There is also a FreeCAD source attached, so you could easily resize or tune the thing using the [original guide](https://www.idig3dprinting.co.uk/news/how-to-guides/create-a-3d-printer-calibration-cube-in-freecad).