Replacement filter compatible with Honeywell U Filter, HRF201B. Compatible with Honeywell HHT270 and HHT290 Series Air Purifiers. True HEPA filtration removes up to 99.97 percent of airborne particles from the air including smoke, dust, pollen, pet hair and dander, mold spores and dust mites. Attached carbon pre-filter reduces VOCs (volatile organic compounds) and household odors from cooking, cleaning and pets. Recommended to change filter every four (4) months for maximum efficiency, or more often in harsh environments. Package contains two (2) replacement filters. Approximate Dimensions: 5 x 10 x 1 3/8 inches.