Hey Weser,
I actually bought one of these from Royal Ind.
For the price vs how long it would take me to make, I just bought one.
I have not used it yet, but from my inspection, they have the 1-1/8" hose attached to the back end and the splash plate over the front of it. the plate then disperses the water out.
Like this...
I have a Royal folder sluice and as I mentioned, the attachable High-banker head as you have shown.
I also went ahead and got some Gold Hog matting to install into my sluice.
So far I am happy with the Royal products. Well built and compact enough to get into some discrete areas.
The bummer for me is - I have pretty much everything I need for prospecting etc....
I just don't seem to have the time - ARRRGG.
I'm out of town this weekend, but next weekend I plan on putting together my recirculating sluice system and trying it all out.
hope this helps.