This is a Dyson style pre-motor conical filter assembly for the Dyson DC49 barrel vacuum cleaners.
It's bright blue in colour and fits inside the cyclonic dust container.
They can be washed, HOWEVER, we strongly suggest you remove the centre plastic part which traps dust at the pointed end, which sets like mud, if it's not removed before washing!
To remove the former inside from the fabric filter part, depress the 3 tiny dimples and they will easily part, and you may see a plug of dust and hair which can be picked out!
As it's light, maximise the saving on postage and buy several of them, or some of the related parts below.
At the moment, standard postage within Australia is capped at a maximum of $25!
