Mechanical Bore Gauge Set without Mechanical Indicator Range 0.163 in to 0.492 in Operation Type Mechanical Contact Style Split Ball Dimension Type Inch Includes Indicator No Maximum Measurement - Inch 0.492 in Minimum Measurement - Inch 0.163 in Requires Indicator Yes Accuracy 118 micronin Contact Point Material Steel Includes Case Yes Series 2421 Repeatability 39micron in