This comprehensive air cleaner uses a robust six stage system to remove pet dander, viruses, fine dust, bacteria, and odors, and you can customize the unit with a filter that addresses your specific air quality needs. The first stage uses nano-silver technology the same technology used to sanitize instruments and surfaces in hospitals to capture germs, pet hair, and large dust particles. The second stage traps pollen larger than one micron and a HEPA filter in the third stage eliminates airborne allergens and mold down to 0.3 microns. The fourth stage consists of the customized filter (pet, toxin, or germ) that you select when you purchase the unit; the pet filter captures and eliminates dander that can aggravate allergies, the toxin filter traps gaseous impurities released from carpets, composite wood furniture, and paint, and the germ filter kills bacteria and viruses like human influenza that can infect children and those with compromised immune systems. The charcoal filter in the fifth stage absorbs odors from tobacco smoke or cooking, freshening the air without producing ozone. The final stage releases negative ions that cause positively charged airborne microorganisms to agglomerate and settle, reducing air stuffiness that afflicts indoor environments. An air quality sensor measures air contaminant levels and changes fan speeds accordingly (or the fan speed can be changed manually) and the integrated ambient light sensor detects darkness and automatically switches the air cleaner to silent mode. Suitable for rooms up to 700' sq. Includes remote control with two AAA batteries. Each filter lasts two years; the nano-silver filter is permanent and rinses clean. Plugs into AC. Specify pet, toxin, or germ filter. 20" H x 21 1/2" W x 7 D. (19 1/4 lbs.)