Mechanical Bore Gauge Set without Mechanical Indicator Range 0.48 in to 0.811 in Operation Type Mechanical Contact Style Split Ball Dimension Type Inch Includes Indicator No Maximum Measurement - Inch 0.811 in Minimum Measurement - Inch 0.48 in Requires Indicator Yes Accuracy 0.000157 in Contact Point Material Steel Includes Case Yes Series 2421 Compatible Dial Graduations 0.000 in 0.0001 in 0.001 in Repeatability 39micron in