Dyson's helpline weren't happy about my problems with this brush. They said that buying through Amazon made my problems Amazon's, although the item is supplied by Dyson through Amazon and the supplier is Dyson. Eventually, I was able to persuade them that I had bought a genuine Dyson attachment.
I own 2 Dyson vacuums - one upright, one cylinder and the brush doesn't really fit either of them. The adapter supplied with it is a crude push fit with the cylinder cleaner hose, but is useless with the upright cleaner (a DC07) which has a hose with a wider diameter than either the brush attachment or the supplied adapter.
There are 3 adapters, but only one is supplied with the brush. The helpline described them as the Circle, the Square and the Triangle adapter, but you can't tell which you have just by looking. I don't know which one they've supplied with the brush. They told me that the correct adapter for my DC07 is the Triangle adapter. They said they'd sent one in about 5 days, but I don't know if they'll charge me extra for this new adapter.
If I hadn't have believed the statement 'Fits all Dyson Vacuums', I would've rung the Dyson helpline first and specified the adapter/s that would fit my machine. So, if you want to buy this model of brush, you might want to ring Dyson on 0800 298 0298 and check that it really will fit your cleaner. It will save you time and hassles.