Designed to fit Blueair Classic 500/600 Series Air Purifiers. Includes Blueair 501, Blueair 503, Blueair 505, Blueair 510, Blueair 550E, Blueair 555EB, Blueair 601, Blueair 603, Blueair 605, Blueair 650E, and Blueair 680I Filtration removes up to 99.97% of airborne particles as small as 0.3 microns in size including smoke, dust, pollen, pet dander, mold spores and dust mite debris Recommended to replace every six (6) months, or more often if in harsh environments Includes three (3) replacement filters Dimensions: 13" x 9.5" x 8.5"