Which of the devices shown in the illustration is designed for both inside and outside measurements? GS-0073

Correct Answer: Option D — C

A vernier caliper, typically labeled as 'C' in standard maritime technical illustrations, features both external jaws for outside dimensions and internal nibs for inside measurements. This versatility makes it the primary precision measuring tool for marine engineers when verifying clearances, shaft diameters, or bore sizes during machinery overhauls.