MODEL "123" BACK PRESSURE RELIEF REGULATOR,GRAPHITE/NBR GASKETS 1/2" SIZE; CF8M BODY & SPRING CHAMBER; S3 TRIM: 316SST WITH TFE SEAT,NEOPRENE (BC) DIAPHRAGM; OPT-39: SOCKET WELD ENDS - (MSDS SPEC REQUIRED); 2-30 PSIG RANGE SPRING; PER SPQ NUMBER 54898 WITH SST CLOSING CAP;