Replacement humidifier filter fits Holmes humidifier models HM1550, HM1555.
Antimicrobially Treated by MicroFree to prevent growth and migration of mold, fungus, algae, and bacteria.
Replace your filter every 4-6 weeks for best performance and comfort
Part number H45 is a 2-pack of filters.
Approx. Measurements: 6-3/4" L X 1" W X 8-1/4" H
Replaces Holmes original part number HWF45, HWF-45