Max is the manufacturer listed max and min expansion range.
When you select this, I'll also show you lines indicating where 10%
and 60% expansion range is. Many people consider 10% and 60% expansion
to be a reasonable usable range for cams, but these numbers may differ
from cam to cam and also depend on your risk tolerance.
Usable is 10% to 60% of the max range, unless a manufacturer publishes
a different number. Metolius is currently the only manufacturer that publishes
a usable range. When you select this option, the entire bar represents the