Style 18 HEPA vacuum filter cartridge. When used with the Healthy Home vacuum Airetight HEPA filtration system, traps and seals-in 100% of dust mites, pollens, ragweed, mold spores, and 99% of pet dander, Model No. 16N5-3. Regular replacement of the Bissell HEPA filter cartridge helps your vacuum operate at peak efficiency. Quantity: 1 cartridge.