It's a bar about 18 inches long (or to your preference) with multiple nozzles on it the nozzles fans' just touch each other to form a water broom. They havecastor wheels on to push them like a broom but I end up useing mine like a lance
Hope this works heres a link to a pdf page from Dualpumps, they call them waterbrooms 4 nozzle or 3 nozzle you put them on a lance extension and a gun to form a water broom.
http://dualpumps.co.uk/images/Catalogue_PDFs/Flat_Surface.pdfMmm I see they do a HYDROBROOM with oscilating nozzles an rotary brushes, never seen one in the flesh, but as there max210 bar to small for my machine (around £250 tooooo much money)