This pic just shows the Unger 'elbow joint'
it is made of cast aluminium, but stresses on all of it conspire to make it wobbly after a while, so you simply do a little cutting and re-drilling and screwing to get everything nice and tight again.
The Ionics residential brush is plastic, so it isn't as robust, but it is lighter, and that makes wuite a difference when you get it up at a great height.
Their commercial type assembly is far more rigid, but from what I can see, you lose out in not being able to angle the brush up when you are working over a conservatory.
But they don't degrade and wear like the Unger ones.
I think that Omnipole do have the facility on their brushes to angle the brush head itself, but I don't personally think this is as good as the Unger set up where you can angle the gooseneck itself.
But again, the Omnipole one is far more robust.
But one more advantage of the Unger setup (and the brush that Peter F supplies) is that you simply pop it off whatever pole you are using, and pop it on to the next one you want to use, ergo you can get away with just one brush, and one pole hose.
The setup is cheaper with Unger, and it isn't as robust as the other systems on offer, but it is so versatile.
Wel that was fun, at least by using i you can post photo's on thesite!
Ian