Parts of a vernier caliper:
Outside jaws: used to measure external diameter or width of an object
Inside jaws: used to measure internal diameter of an object
Depth probe: used to measure depths of an object or a hole
Main scale: gives measurements of up to one decimal place(in cm).
Main scale: gives measurements in fraction(in inch)
Vernier gives measurements up to two decimal places(in cm)
Vernier gives measurements in fraction(in inch)
Retainer: used to block movable part to allow the easy transferring a measurement
A variation to the more traditional caliper is the inclusion of a vernier scale; this makes it possible to directly

by nicholas