This adapter fitting has the M22 Standard male thread at one end (the same that connects to the Rockcar flexible green hose), and has the quick release hose fitting at the other end, common on some Black & Decker, A&R and some other machines.

Solid brass with rubber o ring.  High quality.  High pressure connection.  From Rockcar.  

When in doubt please check your machine and the dimensions on the existing hose/fitting.  

This is type 4 on this guide:

Important: Water blaster manufacturers change hose fittings even between the same models as they change hose suppliers.  Please check your fitting matches the guide before ordering.