LOW TEMPERATURE SHUTOFF (PNEUMATIC) MODEL 135-B,BRASS HEAD,BRONZE THERMAL ELEMENT; STD 1/2"-NPT-MALE INSERTION CONNECTION; BR/SST/CU INTERNAL TRIM,FLUOROSILICONE (FK) SEALS,SST SPRING WASHERS, INVAR ROD; SETPOINT CALIBRATION,-40 DEG F FULL OPEN; OPT-55: CLEANED FOR OXYGEN SERVICE PER SPEC #S-1134;