This is a fancy metal pen-style caliper meant for dentists to use to measure tooth spacings. It doesn’t have a Vernier scale, but instead has two markings on the sliding jaw, one for measurements between the outside faces of the jaws, and one for measurements on the inside.
Location: Box 5
Have you used this tool? Think my description is all wrong? Have a better example? Comment now with any thoughts you have about this tool!