Other systems used in sandpaper include the Japanese Industrial Standards Committee (JIS), the micron grade (generally used for very fine grits).

And, yeah, the amazing part is that this superconductor that you see here is only half a micron thick. It's extremely thin.

As you go farther down this scale here, that's a micron, or a micrometer, and we go all the way down to here to a nanometer and an angstrom. Now, an angstrom is the size of the diameter of a hydrogen atom.