Compatible with HoMedics Oscillating Tower Air Purifier models AT-PET01, AT-PET02, AR-45. Replaces part number AT-OFL. Filtration helps remove up to 99.97% of airborne particles as small as 0.3 microns in size including dust, smoke, pollen, pet hair and dander, mold spores and dust mites. Recommended to replace every twelve (12) months under normal usage, more often in harsh environments. Approximately 10 7/8 x 4 3/4 x 1 1/4 inches in size. Filter-Monster branded replacement filters. Package contains two (2) filters. Filter-Monster branded replacement filter designed to be compatible with HoMedics Oscillating Tower Air Purifier models AT-PET01, AT-PET02, AR-45. Replaces part number AT-OFL. Recommended to replace filter every twelve (12) months under normal usage, more often in harsh environments. Each filter is approximately 10 7/8 x 4 ¾ x 1 1/4 inches in size. Package contains two (2) filters.