Deltronic PPM25 Class X Pin Gauge Sets. 0.0025mm Steps Code PPM25-3825-6275 Range .3825 - .6275mmThe Deltronic Class X Gage set is a unique combination of plug gages offering hundreds of combinations for qualifying hole sizes in and around the nominal size. You can choose any combination of Go No go tolerances or use the range to find the exact size of a hole. This provides standards for zeroing comparators, setting snap gages, micrometer checking, hole center and layout determination, precision arbours for staging parts and checking runout of