A caliper is a tool used to accurately measure the thickness, length, inner diameter, and depth of an object. It is also called a vernier ruler, a vernier caliper, a straight vernier ruler, Calipers, Lounes (Taiwanese), and Nogisu (Japanese). In addition to simple standard calipers, there are many other types, such as dial calipers or attached dial calipers, or digital calipers for when you want to measure values quickly and conveniently. You can choose by using the maximum measurement value (mm) and resolution (mm).