Electronic Digital Caliper, it's very easy to use. It has a hardened stainless steel body for prolonged tool life. Switches from inches to millimeters with the touch of a button. Large, easy to read numbers, reduces error. It can be adjusted to zero at any position. Electronic Digital Micrometer - Provides instant reading. It has an enameled metal body with matte finish, non-glare thimble. It has large, easy to read numbers for error reduction with instant inch/millimeter conversion. It has zero adjust at any position. Thimble lock for measuring like objects.