Convenience is one of the reasons the caliper is often the measurement tool of choice. The basic caliper provides direct size information, has relatively high resolution and is easily adaptable to different measurement applications. Beyond the basics, there are various caliper styles that extend these advantages to special measurement applications.
A caliper consists of two opposing surfaces: a stationary anvil/jaw and a moveable slide. On most calipers, these are made from hardened steel, but optional carbide-tipped or ceramic contact surfaces are available. Calipers also can be equipped with built-in contact tips with unique forms for measuring special part characteristics, or jaws with replaceable and configurable contact points.