I am completing a drywall project and am not good at drywall which means lots of sanding and lots of dust. After ruining my second filter in a week trying to get rid of the dust that had accumulated in the folds I bought this sock and it's a miracle. Enough dust will accumulate over time to restrict the flow, but it can be tapped off or easily scraped off the sock and it's ready for use again. The sock does restrict flow somewhat, but it's worth it for the ease of cleaning and filter savings. Vacuum cleaners should just come with this.