The Mitutoyo 7223 Dial Depth Gage has the following specifications: Range: 0-10mm Stroke: 10mm Graduations: .01mm Accuracy: +/- .015mm Flatness: .005mm Base Dimension: 25mm Diameter Contact Point: Carbide Measuring Force: 1.4N Features: Wide probing range is available with supplied extension rods Bottom surface of the base is hardened ground and lapped for highest degree of flatness. Designed with a back plunger type dial indicator for upward facing readings. (7231, 7237, 7238) Technical Data: Dial reading: 0.01mm or .001" Flatness of base face: 5?m or .0002"