"SERD 0747;1.0 IN. WD;1.0 IN. HT;1.0 LB;C/O NARROW RECTANGULAR HARDENED STEEL BLOCK W/VERTICAL LEGS OF CLOSELYCONTROLLED HEIGHT AT BOTH ENDS;LEGS DIFFER IN HT AND MARKED ""MIN"" AND ""MAX"" TO CORRESPOND W/SERVICE LIMIT ACCEPTANCE DIMENSIONS;SLIDES ACROSS BASE PLATEOF FIXTURE,WHICH HOLDS COMBUSTION CHAMBER,LEGS ACT AS A GO-NO GO GAGE;CHECKSOUTER LINER LG OF COMBUSTION CHAMBER"