DESC: The AllerAir 5000 DXS Series Air Purifier is the safest, most effective air cleaning for tobacco smoke. It features a unique tar-trapping pre-filter that grabs larger particles and tar, which also extends the life of the HEPA filter and carbon filter. Specially blended activated carbon traps up to 400 toxic chemicals found in tobacco smoke. This unit has a micro-wrap filter to deal with small particles as small as the fine cigarette ash and a 3.5 inch extra-deep, 28 pounds carbon filter which increases dwell time, allowing more chemicals, gases and odors to be absorbed.