Uniweld G1S 2-Inch Gauge 0-400 PSI Gold Steel Case, 1/4-Inch NPT Bottom Mount 2 Inch Gauge, 0-3000 PSI, U.L. Listed, Gold Steel Case 1/4 Inch NPT Bottom Mount Brass fitting that is corrosion resistant Oxygen cleaned welding gauge per (A.N.S.I. B40.1) Suitable for oxygen, nitrogen, fuel gases and medical equipment. Recommended for use with compressed gas regulators.