Some years ago I was desperate for a replacement filter for my Craftsman shopvac. The Sears I went to was out of the standard, pleated, paper cartridge that I needed so I broke down and bought a reusable Gortex filter that was $30 or so and on the shelf. It was some of the best money I ever spent. It will not pass any fines (drywall dust, fireplace ash, etc.) in the exhaust. Every once in a while I rinse it off, let it dry and reinstall it.