X-Jet Nozzles contain an internal orifice which is sized to match your GPM/PSI. If you need to replace your X-Jet orifice due to loss or wear and tear this is the part for you. It is also optimal if you have an X-Jet rated for a specific GPM range, and have upgraded your pressure washer to a different GPM range.
Remove the plug fitting form the back of the X-Jet nozzle, then take out the internal spring and orifice from the nozzle and replace with the new orifice. Remember to put the spring back in as well before reinserting and tightening your plug fitting.