Measuring from 0 ~ 12.7 mm High Resolution up to 0.01 mm /0.0005". Switchable between mm and inch, suitable for all klinds of measurement. Hole diameter: 6.5mm, it is removable and can be used on different magnetic base holder stand. Be used to accurately measure small - distances in mechanical and industrial processes without reading errors. An for Ideal tool for mechanical, industrial processes and laboratory use.