Generally
Bearing thread for measuring crank and frame bearing play. It is a thin plastic wire that you put between the crankshaft and bearing, then you tighten the bolts and measure the width of the wire, which flattens out and becomes wider the less play you have. Then measure the width with the included measuring stick. Measuring range is in inches .001″ – .003″ or in millimeters 0.25mm -0.075mm
