Radius Gauge

A simple gauge for in- and outside radiuses from 0.5mm to 5mm in 0.5mm steps.

The number of dots corresponds to the radius in mm, increasing clockwise for the inside and counterclockwise for the outside radiuses.

The half numbers in-between are not labeled, but 2.5mm is between the two and three dots marking :-)

Works best against backlighting.
The images show a proper (4.5mm) and a misaligned (3.5mm) measurement.