Keep replacement filters on-hand so your 3-in-1 Air Purifier + Sound Machine + Nightlight can continue removing dust mites, mold spores and air pollution. Switch out the HEPA activated carbon filter every 90 days and keep breathing easy. Be sure to snag the full Fridababy 3-in-1 Air Purifier + Sound Machine + Nightlight to clear the air in your nursery. HEPA Filter: Removes mold spores, pollen, smoke, odors + pollution from the air; Long-Lasting: Easy-change air filter lasts for 90 days;.