A Vernier Caliper provides a high degree of accuracy in reading of distances. The device consists of a vernier scale – metric as well as inch measurement - with a fixed and a movable jaw. The movable jaw comes with a pointer that slides along the scale. The gap between the two jaws is then read to measure the distance. Vernier calipers can measure internal dimensions, external dimensions, and in many cases, depth using a probe that is attached to the movable head, and which slides along the centre of the body. The attached probe is thin enough to get into deep grooves that may prove difficult for other measuring tools.
The vernier calipers are made of metals or plastic materials. Plastic vernier calipers have, in recent years, grown in demand. The most common plastic material used is ABS. ABS plastics are composed of acrylonitrile, butadiene, and styrene, which are durable materials for the production of plastic vernier calipers.