Starrett 128M Reading Combination Head, with Inside Micrometers, 0-50mm Range, 0.01mm Graduation, +/-0.0001" Accuracy

The starrett combination head for inside micrometers combines the precision of a dial indicator sensor and the linear accuracy of a micrometer. This combination of indicator and micrometer reduces the need for operator "feel" and provides faster readings with increased reliability. For millimeter-reading tools, the head can be adjusted within a range of 50mm. This extends the overall range an additional 125mm. The special no. 81-181J jeweled non-shock Indicator is graduated 0.01mm, range +/- 1mm and reads 0-100mm on both the plus and minus dials. The 250mm master should be used vertically with the shoulder on the indicator end of the head, seated squarely.