Uniweld RV8010 Heavy Duty Single Stage Oxygen Regulator with CGA540 Inlet 3-1/4 inch stainless steel diaphragm CGA540 Inlet, Maximum Inlet:3000 PSIG Large Brass Handle Designed For Heavy Duty Regulator Externally serviceable reseating pressure relief device (PRD). PRD not designed to protect downstream equipment Delivery pressure: 5-125 PSIG