LOW TEMPERATURE SHUTOFF (PNEUMATIC) MODEL 135-S,SST HEAD,SST THERMAL ELEMENT; STD 1/2"-NPT-MALE INSERTION CONNECTION; SST INTERNAL TRIM,FLUOROSILICONE (FK) SEALS,SST SPRING WASHERS,INVAR ROD; SETPOINT CALIBRATION,+50 DEG F FULL OPEN; OPT-55: CLEANED FOR OXYGEN SERVICE PER SPEC #S-1134;