Travel Ultrasonic Cool Mist Humidifier Filter, Clean Control Antimicrobial Material Is Proven To Help Reduce Mold & Bacteria Growth, Extends Lifetime Of Your Humidifier, Filters Water & Eliminates White Dust. Travel Ultrasonic Cool Mist Humidifier Filter, Filters Water & Eliminates White Dust. Humidifier Wick Set for the Crane Travel Humidifier Absorbs water and filters out minerals to assist in making a cool mist Replace filter when it changes color or after one month of usage Includes 5 replacement wicks