Mitutoyo Electronic Internal Caliper Gage These internal caliper gages are designed for measuring Internal Diameters that might be difficult to get to. They are also often galled a Groove Gage because of their perfect design for measuring IDs on internal grooves. Features include... 1.57-3.54" / 40-90mm Measuring Range 0.001" / 0.02mm Resolution 0.0024" / 0.06mm Accuracy 7.56" / 192mm Max Measuring Depth Ball 0.08" / 2mm Radius LCD Analog / Digital Display IP63 Rated Protection SPC Output Function Include... Zeroset Preset Auto Power Off In / Metric Conversion Data Hold Min / Max Value Hold Used to be Mitutoyo # 209-910. New model # 209-950 not available until 2-25-2022.