Keep your home's air clean and healthy with the Aller Air Model 4000 Air Purifier. Rid your home of dirty contaminates and nasty airborne particles. Durable casters allow you to move the machine easily around to needed rooms of the house. Breathe easy knowing your air is clean. The AllerAir 4000 Exec Air Cleaner can eliminate noxious gases and odors from the air you breathe. The 10 lbs of activated carbon along with the HEPA filter provide the clean indoor air you need for good long term respiratory health. This particular air purifier has many exciting features. There is a cleanable pre-filter to collect those larger particles in the air such as lint or paper. Paint fumes, chemicals, furniture glue, cigarette smoke and other noxious gases and odors are absorbed by the MAC-B filter. Finally, the HEPA filter traps 99.97% of solid particles as small as 0.3 microns such as pollen, dust and pet dander. It has a three speed fan, an all metal construction to avoid plastic vapors and a cylindrical shape to maximize air flow. This is an excellent choice of a fresh air purifier because it can change air every 6-7 minutes in small areas but also works in areas as big as 1200 square feet in 30 minutes and has a low electricity usage. Best of all it is quiet enough to use at night, reassuring you are breathing fresh air all day and all night. There is also a five year guarantee.