One of the issues with using quick disconnects (QD) is the extra bulk they add to the high pressure hose to spray gun connection. In order to keep the hose from binding under pressure, I've found that a swivel is needed. The bulk of the QD/swivel combo forced me to test many different combinations to come to this solution.
This Mosmatic spray gun has an amazing stainless steel built in swivel that eliminates the need to add a separate connection. I know this is expensive, but it is the best on the market.
You have buying options:
Spray Gun Only
Added Quick Disconnects to connect to your pressure washer hose.
1/4" MTM Stainless Male Coupler
3/8" MTM Stainless Male Plug
3/8" MTM Stainless Female Coupler
M22 to 3/8" MTM Twist and Plug
Added Adapter if you have a pressure washer hose that is M22 15mm instead of the standard 14mm connection