The new stainless steel torpedo for a better plastic flow performance. This new stainless steel cast part replaces the existing torpedo in V2 models for a better plastic flow performance. Disassamble the nozzle plate first. Simply unscrew four bolts on the nozzle plate when the barrel is heated upto melting temperature for the material inside. Replace the torpedo with the same orientation then put the bolts and the copper seal back in place. Make sure the copper seal is mounted well when you mounth the nozzle plate. This is a spare part and no need to buy along with the machine.