The model 450 heavy duty regulator is manufactured using only the highest quality industrial bronze and brass material. A tamper-proof, self seating high pressure relief adds another degree of safety and durability. The oversized bronze adjusting screw makes pressure adjustments easier to reach those needed pressures. It also has a stainless steel diaphram for a long life and dual 2-1/2" gauges for easy pressure identification. Delivery Pressure Range 0-125 psi. Inlet CGA 540. Outlet 9/16"-18 RH. *7 year warranty