Meyer Class Z Metric Pin Gage Set Meyer's Class Z Gage Pin Sets are now made to a closer tolerance (0.0025mm), are more accurate, and are a better solution for your needs. The old Class ZZ had a size deviation of 0.005mm. The new Class Z has a size deviation of 0.0025mm. Features of this set include... 12.73mm to 15.31mm Class Z Gage Pin Set 130 Pieces in .02mm increments 51mm Overall Length Sets are traceable to NIST Boxes and Gages are both marked Each gage has an 8 microfinish or better Please specify PLUS or MINUS when ordering. PLUS (Go) tolerance = +0.002mm / -0.000mm MINUS (No Go) tolerance = +0.000mm / -0.002mm