In machine-shop usage, the term "caliper" is often used in contradistinction to "micrometer", even though outside micrometers are technically a form of caliper. In this usage, "caliper" implies only the form factor of the vernier or dial caliperA caliper is a device used to measure the distance between two opposite sides of an object. A caliper can be as simple as a compass with inward or outward-facing points. The tips of the caliper are adjusted to fit across the points to be measured, the caliper is then removed and the distance read by measuring between the tips with a measuring tool, such as a ruler.It is used in many fields such as mechanical engineering, metalworking, forestry, woodworking, science and medicine.FEATURESNew designed dial movement for ultra smooth sliding and high shock protection.Can measure OD, ID, depth, and steps.Lock screw for dial bezel and for holding the sliding jaw position.Models available with carbide-tipped OD and ID jaws.Supplied in fitted plastic case.Dial Type Vernier CaliperSPECIFICATIONThe measuring range of a caliper is the difference between the largest value and the smallest value that it can measure.The measuring range of most dial calipers is 150mm (6 inches), although calipers with ranges of between 100mm (4 inches) and 300mm (12 inches) are also available.When selecting a caliper, bear in mind the approximate size of the object you are measuring. To measure larger objects, you will need a caliper with a larger measuring range.The graduation of a dial caliper is the smallest distance it can measure; the value of a minor increment on the dial scale.The graduation of most dial calipers is 0.02mm for metric versions, and 0.001 inches for imperial dial calipers.Graduation is normally indicated on the face of the dial.