The inch version of these calipers has a direct-read scale with 0.1" markings and a secondary micrometer-style scale that reads down to 0.001"! (Yeah, right...) Realistically, it's maybe accurate to +/-0.010". The metric version has a direct-read scale with 2mm markings and a secondary scale with 0.1mm graduations.UPDATE: A metric version has been added! The same slider part is used for both. These parts were printed in PLA with 0.2mm layers, 3 perimeters and 20% infill. If you don't have a heated bed, you should print the body and slider parts with a raft to make sure they are flat. You should print them fairly slowly to retain as much detail as possible. After printing, you'll probably need to lightly sand some of the parts, particularly the inside threads on the nut, to remove any lumps. To Assemble: