Vermont Master Setting Discs Class XX - Various SizesThese Vermont Master Setting Discs are used to calibrate measuring equipment like a Micrometer or Snap Gage. Designed to satisfy traceability requirements of your quality control system, these Master Setting Discs are a must for your calibration lab and inspection areas. These Vermont Master Setting Discs are available in 3 tolerance classes: XX, X and Y. Each Master Setting Disc includes a Certificate of Accuracy. Features include XX Class Bilateral