This quality tool is the ideal implement for measuring thicknesses, inner diameters or drilling depths. It measures from 0 to 150 mm with a scale-reading precision of 0.05 mm. Depth measurements are made at the bottom end of the calliper by means of the flat depth probe, measurements of inner span with the top measuring (inside) jaws. The vernier scale (the slide with the second scale has this name) displays tenths of millimetres with graduations of 0.05 mm. Full millimetres are read directly on the main scale to the left of the 0 of the vernier scale; the tenth and hundredth millimetre are read at the place on the vernier scale where the graduations of both scales are in congruence.