Deltronic HTM24 Class X Pin Gauge Sets. 0.005mm Steps Code HTM24-21.26-25.585, Range 21.2600 - 25.6700mmThe 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