The Nilfisk IVB7 M wet and dry industrial vacuum cleaner and the Nilfisk-ALTO WAP Attix 7 industrial wet and dry vacuum cleaner plastic sack, packet of 5 they also fit the Nilfisk-ALTO Attix 965-21 SD XC and the Nilfisk-ALTO Attix 961-01 and the Festo Hilti Makita and Stihl branded vacuum cleaners
These are a pack of 5, open top plastic sack that may suit wet or dry use. The disadvantage is they tend to wrap themselves around the filter cartridge, due to air getting between the container and the sack, because of the creases where it's trapped between the container and the vacuum motor head. But they're better than a black garbage bag!
Maximise the saving on postage and buy some of the related parts below, such as a new hose, and a new filter or a new floor tool or round brush.
At the moment standard postage is capped at a maximum of $20 Australia wide,