This is something that might be developed to help people who cannot find their insulator in the CD system. The graphic shows an example as well as demonstrating how easy this visual aid would be to use. Anyone not able to find their CD could look at a chart, find the closest match, and be directed to the assigned CD.

If this sounds good to someone, I would love to see somebody take my idea and develop it. I am trying to write some books or it would have been done!