SVG panel dimensions and Eurorack

Breaking out a new topic from the thread on SVG pixels/old versus mm/new, I always wondered why 5HP is one inch. Sure enough Eurorack is based on the 19 inch rack ISO standard. [I am new to all this.] Here’s all the dimensional reference data, and shows where the magic number 128.5mm comes from.

An amusing blending of inches and metric living together in Europe.