Ordering Description Product number Description: ELC4-125-540R EDGE Series Liquid Cylinder Regulator- Oxygen Product number: 0781-5199 Description: ELC4-125-580R EDGE Series Liquid Cylinder Regulator- Inert (Nitrogen, Argon, Helium) Product number: 0781-5200 Description: ELC4-125-320R EDGE Series Liquid Cylinder Regulator- Carbon Dioxide Product number: 0781-5201 Description: ELC4-125-325R EDGE Series Liquid Cylinder Regulator- Inert (Nitrogen, Argon, Helium) Product number: 0781-5202