Fits Bionaire models BCM1845, BCM1845C, BCM1850 and BCM1855 * Bionaire humidifier wick replacement filters. * Measures approximately 7 1/2" H x 5 1/4" ID x 7 1/4" OD x 1" Thick. * With antimicrobial agent! * Honeycomb filtration to trap mineral pollutants found in water and help prevent them from entering your home.