209-360 Mitutoyo Internal Dial Caliper-Type Gage 3.2" - 4.0"Mitutoyo Internal Dial Caliper Type Gage For checking internal bores, recess diameters and grooves. Features include 3. 2" 4. 0" Measuring Range 0. 0005" Graduations +0. 0015" Accuracy Max Measuring Depth: 3. 3" Max Groove Depth: 0. 31" Minimum Groove Width: 0. 06" Ball Contact Points: 1mm Radius Spring loaded opening Press Button for closing arms. Arms automatically open when button is released Unit is spring loaded and makes point contact at