Mechanical calipers are precision measuring tools used to determine the dimensions of an object. They typically consist of two arms, one fixed and one movable, which can measure internal, external, and depth dimensions. The measurements are read from a scale, often marked in millimeters or inches, allowing for accurate readings. These tools are commonly made of metal or plastic and are widely used in various fields, including engineering, woodworking, and metalworking. Mechanical calipers are valued for their simplicity and reliability, as they do not require batteries or electronic components, making them easy to use in various environments.