So nice to have a replacement filter set for my old vacuum cleaner. I wash one set and let it dry, change one of the spare sets and just keep working. Works great during our renovation project, phase I or II? LOL It's not easy to keep it clean while working, especially when I only had the original filter set. Drywall dust is by far the hardest hit on filters as it gets in everywhere and quickly overwhelms the filters! The price was great and having four spare kits really helps get the job done! ;-)