B-10/B-20 Universal Concentricity Gages comprised of three main components for assembly
#1) selection of standard or precison accuracy
#2) selection of main rollers
#3) select an indicator(s) and/or other accessories
There are two classifications calibrated and directly traceable to (N.I.S.T.)
Standard Black Gages are guaranteed to be better than ≤ 4µm (.00016") accuracy.