Hi, I am having trouble understanding the SMT electrolytic caps footprints. Here is an example from the KiCAD library that is “6.3x3.9”.

This page indicates that the numbers are the X and Y dimensions of the cap package.

By moving the cursor over the footprint I can see that the 6.3 appears to be the diameter of the can. I can’t see what the 3.9 relates to. It doesn’t seem to be the Y dimension. What is it?

Thanks!