Nozzles attach to MIG (metal inert gas) guns and focus shielding gas on the weld pool in gas-shielded MIG welding tasks. The shielding gas keeps airborne contaminants out of the weld pool to help avoid pores, cracks, or excessive spatter in the weld. MIG gun nozzles must be cleaned or replaced regularly to maintain proper gas flow. They are compatible with MIG consumables and guns from specific brands and series. A complete MIG gun setup includes a nozzle, contact tip, gas diffuser, insulators, conductor tube, and gun liner.