6.2601"-7.0100" (159.01Mm-178.05Mm) Tool Steel Class Z No-Go (Plus) Ring Gage. Class Z, Bright Tool Steel, No-Go (Plus) Custom Steel Ring Gage. Perfect For Use As Masters For Bore Gages And Internal Micrometers. Use Vermont Gage Ring Gages To Efficiently Inspect External Dimensions Of Manufactured Parts. With A Go And Nogo Ring, An Inspector Can Quickly Pass/Fail Parts Without Taking Time Consuming Readings From An Indicator. Available In Master (Bi-Lateral Tolerance), Go (Minus Tolerance) Or No-Go (Plus Tolerance). Nist Traceable. Certificate Of Accuracy Included. Vermont Gage Usa Part #231417210. At Checkout, In The 'Additional Instructions' Field, Specify The Ring Gage Inside Diameter Within The Range Specified.