We have two constructor brushes, slightly heavy compared to say a Gardiner universal brush (which is what we are using at the moment)
The problem with the red cannons breaking as now been resolved, yes you can change the configuration of the bristles, i think there is a choice of 4 types, so you may want to use lets say the the original bristle pack, which is ideal for UK regular window cleaning or you may want the Commercial bristle pack, as the title says or you want to mix them about.
its a very efficient cleaning brush, probably due to the amount of bristles and the water rinse bar is situated above the brush, so you are always rinsing on the down stroke