Looking at the items for sale on a well known tooling site, I found this description for a lever type DTI that clearly shows the face of the instrument printed with " and the word 'in'
FINGER DIAL TEST INDICATOR
SHOCK RESISTANT
CLAMPING DIAMETER 8MM
PROBE LENGTH 13.5MM / 0.53"
PRECISION GEAR DRIVEN DESIGN WITH SMOOTH MOVEMENT
ADJUSTABLE FACE
RANGE 0-0.2"
METRIC GRADUATIONS 0.0005"
No wonder people get confused.
Brian