"Doug Kanter" wrote in message
...
I know - measuring depth. But, my ex is handling an estate sale, and found
a
Starrett model 400 depth micrometer in perfect condition. We're wondering
who uses a tool like this so perhaps we can target the sales process more
accurately.

A machinist would use it. Anyone who works with metal accurately. Lathes,
milling, maybe even CNC.