Honeywell factory original, OEM FC200E1011 Pleated Air Filter (2 Pack), 20" x 20" x 4", MERV 13 A factory original, OEM replacement filter for the Whole House Electronic Air Cleaner F200, F100, F150, F35, F25, F27. Replace the filter every 6 to 12 months. Filter measures 20" x 20" x 4" Since 1885 Honeywell has been providing customers with cutting-edge technology in the home comfort industry. From the first thermostat to today"s innovative Indoor Air Quality products, Honeywell continues to be a leader in the home comfort market.