With its slim, space-saving tower design, this air purifier offers out-of-the-way placement while effectively delivering cleaner, healthier indoor air to rooms up to 80 square feet (9 by 9 feet). Choose from three speed settings: low for quieter operation, medium for continuous use, or high for poor air-quality conditions. Offering a CADR of 55, the unit's True HEPA filter removes up to 99.97-percent of airborne particles as small as 0.3 microns from the air that passes through it, effectively reducing smoke, dust, pollen, mold spores, pet dander, and other airborne particles that can make a room feel stuffy. To help freshen the air naturally, the unit also offers an optional ionizer, which releases negative ions into the filtered air. The negative ions connect with positively charged particles to form larger particles that can be more readily picked up by the filter. Even more, the air purifier comes with a washable pre-filter, which helps capture larger particles and extends the life of the HEPA filter. The air purifier measures 11-2/5 by 8-1/5 by 15-2/3 inches and carries a five-year limited warranty.