The Filtrete™ ULTIMATE room air purifiers (FA-T10AB / FA-T20AB) provide high-efficiency indoor air filtration. It is equipped with the unique 3M patented electro statically charged replacement filter, which attracts and captures microscopic allergens such as pet dander, dust mite debris, pollen, smoke etc. efficiently yet offers better air circulation. The simplified all-in-one replacement filter and the filter change indicator allow the user be aware the operation status and exchange the filter very conveniently yet without compromising the performance.