For fine dust filtration. For vacuuming household dirt and debris, and fine dust like cold ashes, cement dust and drywall dust. For dry pick-up only. Fits most Vacmaster Wet/Dry vacs 12 to 16 gallon. Fits most Shop-Vac® Wet/Dry Vacuum Cleaners (12 to 14 gallon).* *This is not a product of, nor is it sponsored or endorsed by Shop-Vac®. Shop-Vac® is the registered trademarks of the Shop-Vac Corporation.