The 212 comes with a regulator and hose assembly. You can reverse the polarity to run flux-core wire, but if you pay this much for a MIG machine, you’ll be running shielding gas. For welding mild steel, C25 (75 percent Argon and 25 percent Carbon Dioxide) is best, although you can run straight carbon dioxide. You can buy or rent gas cylinders at your local welding supply shop. Miller’s EZ-Change Low Cylinder Rack allows you to roll larger bottles straight on the cart without lifting.