This part isn't as complicated as it may seem.  It is a female part that fits anything low pressure (garden hose) related.

It is 3/4" Female BSPM to 3/4 GHT.

This adapter is used to replace the stock plastic adapter on most pressure washer inlets. Works for Comet, AR, Karcher, Etc

BLACK FILTER IS THE GARDEN HOSE SIDE.  THIS SHOULD ONLY BE HAND TIGHTENED.