Genuine Kjellberg G4030 swirl gas cap (3.0 mm bore) for mechanised plasma cutting at 90 A to 200 A. The swirl gas cap fits over the nozzle and directs the secondary (swirl) gas around the plasma arc, helping to constrict the arc, stabilise the cut and shield the nozzle from spatter. Replace it when it shows heat damage, spatter build-up or a deformed bore, as a worn cap reduces cut quality and shortens the life of the other consumables.