More than likely this should be a M22 threaded fittings. That is pretty common for units like yours. If that is the case, then the kit you are asking about is more or less what you would need. If you have M22 threaded fittings. More than likely there is going to be some plastic couplers at the end of the hose on each side. If there is, then this would be M22.
Thanks,
Pressure Washers Direct