Keeps your watch hand pressers vertical.
Current ID is 6.2mm, a little tight for 6mm OD setters, may need to drill out with a 6mm or even a ¼ inch drill bit (spinning in reverse works well for PETG) if you're having tolerance issues. Setters need to slide freely but without wobble.
No supports, print upside down, 0.2mm layers.
The author hasn't provided the model origin yet.