.1801"-.2810" Class Zz Black Guard™ Custom Economy Step Gage, Pin Minus, Step Minus, Single End Member Only Class Zz,Pin(Large) Diameter Minus,Step(Small) Diameter Minus Class Zz +/- .0002" Gage With No Handle, 1/2" Step Length, .100" Max Step Diameter Reduction, 2" Long, 52100 Tool Steel 60/65 Hrc, 10 Microinch Finish Or Better, Round Within 1/2 Of Tolerance, Nist Traceable, Certifiacte Of Accuracy Included. Used For Checking Go & Nogo Tolerances Simuataneously Or For Checking Stepped Id's. Vermont Gage Usa Part #921203210. At Checkout, In The 'Additional Instructions' Field, Please Specify The Pin Diameter And Step Diameter. For Example: .1750" Pin And .1680" Step.