SPI Digit Outside Micrometer Set 0-4" Features include... Measuring Range: 0-4" Graduations: 0.0001" Ratchet Thimble Accuracy... 0-1" model: + 0.0001" 1-2" model: + 0.0002" 2-3" model: + 0.0002" 3-4" model: + 0.0002" Face Material: Carbide Includes Setting Standards Spindle Lock Fitted Case Certificate of Calibration