Humidifier + Air Filter. Patented reinforced design for longer life and better efficiency than standard expanded wicking filters. Traps impurities in the water. Anti-microbial treated. Fits Holmes HM650, 725, 726, 730, 1550, 1555. Fits Duracraft DH799, 800, 803, 804, 805, 806, 807, 812, 815, 821, 822, 823, 824, 836, 837, 837B, 840, 950, DA1005, 1007, 7800. Fits Kenmore 14102, 14108. Fits Honeywell HCM3040, 3060, HCM750, 750-TGT. Fits White-Westinghouse WWHM7250.