Vernier Calipers

Vernier Calipers
A Vernier Caliper is a device used to measure the dimensions of an object. The Vernier Caliper includes a Vernier Scale with a fixed jaw, and another jaw, with a pointer, that slides along the scale.
Vernier Caliper with 2 sets of Jaws can measure the Outer Diameter (OD) or distance from 2 points with the larger, lower jaws. The upper jaws are used to measure the Inner Diameter (ID).