The Starrett 224, 224m series interchangeable anvil micrometers feature a wide range of measurement and flexibility. Each micrometer is equipped with a series of easily interchangeable anvils, thus providing the full range in steps of 1 in. or 25mm with a single micrometer. This model features 50-150mm measuring range. smooth friction thimble for uniform pressure, the combination ratchet and speeder for uniform pressure and quicker adjustment, or a plain micrometer that depends on your own feel. Recommended for mechanics, automotive service and machine shops, toolrooms, inspection departments and wherever gaging involves a wide range of measurements. This model includes these standards: 50, 75, 100, and 125mm. 50-150mm, 0.01mm grad.