Nilfisk Action A300 Series and Nilfisk Action Plus Vacuum Cleaner in Maroon vacuum cleaner dusting brush. This "round" dusting brush is found in the on-board tool compartment. It's ovular in shape as photographed, and has an internal 32mm neck diameter.
As it's light, maximise the saving on postage and buy some of the related parts below, such as the dust bags, the filter or a new floor tool or a hose.
At the moment, standard postage within Australia is capped at a maximum of $20!