Vacmaster fine dust cartridge filter. For vacuuming household dirt/debris and fine dust like cold ashes, cement dust and drywall dust. Captures particles down to 1 micron in size. Fits Vacmaster Professional Beast Series VFB511B 0201, Vacmaster VWMB508 0101, VF408, VF409, Vacmaster Professional VF410P and VF410P 0201, Cleva Industrial VF408B. Also fits Shop-Vac hang up vacs, 5 gallon contract portable, FloorMaster Plus, AllAround Plus and Heavy Duty Portable. **This is not a product of, nor is it sponsored or endorsed by Shop-Vac. Shop-Vac, Hang Up, FloorMaster and All Around are registered trademarks of the Shop-Vac Corporation. This cartridge filter comes with two retainers. For best results, use the retainer that came with your wet/dry vacuum.