If your pressure washer trigger gun is a new Karcher HD Eazy Lock (Eazy Force) style, like the photo below, then you need the new karcher HD connector.
[caption id="attachment_6837" align="alignnone" width="480"] Easy Lock Karcher Gun[/caption]
This is how it is like when it is assembled with foam cannon and eazy lock trigger gun.
foam cannon and trigger gun is not included in this connector.