Class ZZ Go Pin Gauge, Material Steel, Finish Black Oxide, Diameter 0.5480 in, Diameter Increment 0.0005 in, Diameter Range 0.5010 in to 0.6255 in, Diameter Sub-Range 0.5255 in to 0.5500 in, Dimension Type Inch, Gauge Type Go (Plus), Included Certification Certificate of Accuracy with NIST Traceability, Surface Finish 10 Microinch or Better, Tolerance 0.00020 in, Tolerance Class ZZ, Hardness RC 60/65, Long Form Calibration Certificate No, Overall Length 2 in, Standards ISO 17025