Honeywell 50250 99.97% Pure HEPA Round Air Purifier True HEPA filter removes 99.97% of all airborne particlesfrom the air passing through the filter such as pollen, cat dander,household dust, tobacco some & mold spores Product Features Round air purifier or larger rooms (up to 390 square feet in size) Permanent True HEPA filter removes 99.97 percent of common airborne pollutants as small as 0.3 microns Glass-fiber HEPA material also helps remove airborne particles, viruses and bacteria 360-degree airflow, 3 speeds, carbon pre-filter Measures 18 by 18 by 19 inches; 5-year limited warranty The positive reviews speak for themselves for this air purifier. It is highly rated by Consumer Reports and has many good reviews on Amazon.com. I thought I would address the "supposed" negatives people mentioned in other reviews, regarding the noise level and the led light on the unit. I recorded a video on youtube (too long to upload here), that will let you hear and see these "issues" for yourself to make your own decision (just do a search for "Honeywell Enviracare 50250 air purifier" and you should find it). To me, these aren't issues at all. I was shocked that it made a difference in my allergies after the very first night of use. I can actually breathe out of my nose while sleeping now, without having to use one of those breathe right strips. Worth every penny!