Long term customer
I'll always buy my vacuum cleaners or parts here.

The Vacuum Doctor
Thanks Herman! You rock! Andy
Replacement barrier sack filter, for the Nilfisk VP300 HEPA commercial vacuum cleaner. SIMILAR to the photograph.
These shouldn't be washed, just gently vacuumed should they get dusty.
As a rule of thumb, the dustbag filters out dust greater than 50 microns, about the diameter of a human hair. This filter probably filters down to about 8 microns, and protects the HEPA filter.
The HEPA filter will filter down to .003 of a micron, and should probably be replaced each couple of years.
At the moment, delivery is capped at $20, so, how about choosing to maximise the saving on postage and buy several Puregiene toilet rolls a box of Tissues and some soap or maybe some packets of dustbags, or a hose or a new floor tool, or some other accessories!