RQRD TO CHECK HIGH PRESSURE COMPRESSOR REAR CASE 13TH STAGE GROOVE ON THE PRE MACHINE OPERATION PRIOR TO PLATING AND FINISH MACHINE OPERATION AFTERPLATING;GAGE IS RECTANGULAR STEEL BAR W/BRAZED TUBULAR HOLDER ATTACHED TO BAR WHICH SUPPORTS DIAL INDICATOR;THERE ARE 2 REST PADS AND 2 CARBIDE CONTACT POINTS;SERD 1471;26.3 IN. LG BY 2.0 IN. WD BY 3.0 IN. HT;WT 5 LBS