Fowler 54-860-243 Electronic IP54 Blade Micrometer, 2-3"/50-75mm Measuring Range, 0.00005"/0.001mm Resolution, RS-232 Output Digital outside micrometer with a choice of measuring range and a blade-style anvil/spindle pair measures groove diameters of shafts and workpieces with narrow or recessed features LCD performs direct inch/metric conversions and has a switchable resolution of 0.00005" and 0.001mm Friction thimble provides smooth and quiet operation, and is suitable for one-handed operation Certified IP54 for dust and water protection RS-232 output provides ability to export readings to a computer (cable not included)