"GAGE,CONTOUR,FLANGE;USED TO INDICATE THE ALLOWABLE AREA FOR REMOVAL OF MATERIAL FROM TUBE END FLANGE OF P/N 2489968 OR P/N 2494428 INPUT COUPLING ASSY DURING BALANCING OPERATION WHEN OVERHAULING THE PTO SHAFT,LOCATES ON FLANGE TO EXPOSE ONLY THE AREA ALLOWED FOR MATERIAL REMOVED;MEASURES 2 IN. LONG,3 5/8 IN. DIA.,MATL CRES,WEIGHS APPROX. 1 LB. 2 OZ."