This is a tool for measuring the external radius of a round part of an object. It's particularly useful when you are trying to create a 3D model of a real thing.
There are two versions (for now), one that goes from 1 to 10 mm, and another that goes from 6.5 to 12.5 mm, both in steps of 1 mm.
For best results, print as-oriented in the .stl file (the text on the build plate).
The author marked this model as their own original creation.