A caliper is a measuring tool used to accurately determine the size or distance between two opposite sides of an object. Calipers are commonly used in manufacturing, engineering, and a variety of other industries to measure the thickness, diameter, or distance between surfaces. There are several types of calipers including digital calipers, dial calipers, and vernier calipers, each of which uses a different method of measuring and displaying the dimensions of an object. Some calipers use a mechanical system, while others use digital technology. Calipers are typically made of metal, plastic, or a combination of materials, and are designed for durability and precision.