I bought the FilterPal after looking through a few ShopVac filters. I often use my vacuum outside and pick up a lot of organic material. This is a great way to clog a filter quickly and even with a blast of compressed air the filters will get that clean before the pores become permanently clogged with this material. Sign in to FilterPal. This is a very simple idea that works well. It has a much larger air passage area, so the vacuum cleaner runs longer before it has to be stopped to clean the filter, without the suction power being noticeably reduced. While the portion of the FilterPal that comes in contact with the filter can become clogged, a significant portion of it hangs into the canister bowl and stays mostly clean. I never had to stop in the middle of work to clean my device. I use a zip tie to make sure it's secure around the rim of the filter housing. The first few times I used it, the rubber band on the FilterPal didn't hold it in place and it slipped off, exposing a few millimeters of the filter. Since then no more problems with slippage. I waited too long to buy this and one of them would have saved hundreds on previous filter purchases. I've had the same vacuum cleaner for almost 20 years.