Patented reinforced design for longer life and better efficiency than standard expanded wicking filters. Traps impurities in the water. Anti-microbial treated. Fits Holmes HM1800, 1840, 1845, 1850, 1851, 1855, 1865, 1888, 1889, 1895, 1975, 2059, 2060W, 2090, 3000 (HM4000 - requires 2 filters), (HM3800 & 3850 - requires 3 filters). Fits Sunbeam SCM1895, 1896, SCM1866. Fits GE 106609, 106663, 106763. Fits Bionaire BCM-1845, BCM-1855. Fits White-Westinghouse WWHM1840, 2090ZE.