29mm 1 1/8" Dial Diameter Suitable for rapid, accurate measurement of size, concentricity, wear, taper, etc., in a wide range of bores. For workshop and inspection use. All models have one fixed and one moving anvil and a self-adjusting centre shoe. A 'datum point' can be set by using a setting ring of a known diameter or a micrometer. ' Zero' the gauge to this datum point by rotating the bezel to align 'zero' with the indicator. To check a bore is within tolerance, the limit hands can be fixed as required. All anvils are spring loaded to expand into the bore. For accurate reading ensure the stem of the gauge is parallel to the axis of the bore. This can be checked by 'rocking' the gauge back and forth until the smallest diameter is found. All models have inter-changeable anvils to cover a range of bore sizes. Supplied in a tough hard case. Type - Metric Graduation: 0.01mm Face Dial: 57mm Reading: 0-100 Travel Per Rev: 1mm Total Travel: 3mm