... :GCr15 3.Type:Various types (Metric,UNC,UNF,BSW) 4.Precision:5H,6G,7H Metric go no go thread gaugesFeatures: ... 1.Gauges:Metric go no go thread gauges2.Material ... :GCr153.Type:Various types (Metric,UNC,UNF,BSW)4.Precision:5H,6G,7H 5. ... question ,please feel free to contact with us. Metric go no go thread gauges