Check the listing for details. Mitutoyo Internal Groove Dial Caliper Comparator Gauge Gage 30-50mm / 0.01mm. Condition: New. Listed at 247.95 USD. New in box. Made in the Czech Republic by Mitutoyo Germany. Includes factory test certificate with data. $744 MSRP Model #: 209-304 Range: 30-50mmGraduation: 0.01mmAccuracy: +/- 0.03mmMax. Measuring Depth L: 85mmMax Groove Depth A: 7mmMin. Groove Width B: 1.2mmMeasuring Contact Type: B Size: 1mmWeight: 185g See last photo or additional dimensions NOTE — This is a comparator gage and must be set with a setting ring, micrometer, caliper, etc… You set the reference measurement using a micrometer, etc, by the rotating dial and locking it in place. Subsequent measurements will show you variance from the reference. In other words, this is not a direct reading gage and does not display an absolute measurement. You obviously can use it to arrive at absolute measurements, it just takes a few steps and some arithmitic. Half-ball-type carbide measuring contacts. Inside dimension (ID) measurement capability for making comparison measurements of hole diameters and groove and tube thickness Spring-loaded for point contact at constant measuring pressure Dial display provides precise, readable measurements in metric units IP65 rated _gsrx_vers_1547 (GS 9.4.2 (1547))