Uniweld’s G4 welding gauge is suitable for use with oxygen, nitrogen, fuel gases, and medical equipment which are non-corrosive to brass and bronze. The gauge is housed in a 2 inch brass case with a 1/4 inch NPT bottom mount connection. The gauge has a twist on polycarbonate lens and a pressure range of 0-200 PSI. Recommended Part No. GB20S 2 inch Protective Rubber Gauge Boot for additional protection for your gauge. Gauge is recommended for use with compressed gas regulators.