this kind of micrometer is tiny but use conveniently and exactly .We have Mitutoyo brands which is the best in the area

 model                            range                   index of precision

368-906                          2--3mm                0.001

368-907                           3--6mm                0.001

368-901                           6-12mm                0.001

368-902                           12-20mm               0.001  

368-953                            20-50mm              0.001

368-954                            50-100mm             0.001

368-905                            100-200mm            0.001