Ultra-Web Cartridge Filter is designed for wet or dry pickup in full-size vacuums. Nanofibers make cleanup easy especially for small, dry debris and wet materials, such as cold fireplace ash, auto refinishing, cement dust, sawdust, and drywall dust. Filter installs easily and can be removed easily. Filter does not fit Hang Up Vacs, 5 Gallon Contractor Portable, Floormaster Plus, All Around Plus, Heavy-Duty Portable, 1x1, BullDog Portable, Mighty Mini, Mini Hangup, Hippo, or All Arounds with 1-1/2 or 2 Gallon tank sizes..