The Nilfisk BA600 walk behind battery powered automatic floor scrubber and the Nilfisk BA700 and the Nilfisk BR1000 and the Advance Hydroretriever 3800 rider scrubber brush holder spacer. Three are needed per brush/pad holder.
At the moment, standard postage within Australia is capped at a maximum of $25 so maximise the saving on postage and buy some of the related auto scrubber parts below!