Lyman Electronic Calipers precisely measure dimensions and display it on a digital LCD readout. It can easily be switched back and forth between metric and imperial measurement systems and maintain an accuracy of 100 microns (0.1mm) (.001”). As well as external dimensions and a depth gauge, the design also accommodates internal measurements like identifying the internal diameter of a case mouth for example. The Lyman Electronic Caliper also comes with a useful storage case to protect your delicate and precisely calibrated measurement tool.