Model 135 Rev B Low Temperature Shutoff (Pneumatic); Brass Head And Thermal Element; Standard 1/2" NPT Male Insertion Connection; BR/SST/CU Internal Trim, Fluorosilicone (FK) Seals, Stainless Steel Spring Washers, Invar Rod; Setpoint Calibration, Per SPQ Number 53708 With Special -4 Deg F (-20 Deg C) Full Open; Opt-55: Cleaned For Oxygen Service Per Cashco Specification S-1134