"USED DURING DEPOT MAINTENANCE OF PUMP AND MOTOR ASSEMBLIES OF THE F-15E INTEGRATED DRIVE GENERATOR,TO MEASURE PISTON BORES OF P/N 735609 CYLINDER BLOCK TO DETERMINE GROUP SIZE,BORE WEAR,AND ROUNDNESS;MOUNTS ONTO GAGING HEAD OF M01-10M MEASURING GAGE;APPROX 3 IN. LG;APPROX .50 LB;MATL STEEL;SERD NO. 5124"