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" or 25mm with a single micrometer. This model features 0-4" Measuring Range. Combination ratchet and speeder for uniform pressure and quicker adjustment. 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: 1", 2", and 3". 0-4", .001" Grad.