Extended Life Humidifier Filter (Model WF2), which is a replacement filter for various humidifier models. Key features and information include: Function: Removes minerals and pollutants from water used in humidifiers. Antimicrobial Treatment: Helps prevent the growth and migration of mold, fungus, algae, and bacteria on the filter. Compatibility: Fits Vicks V3600, V3500, V3100, Kaz 3020, and Robitussin DH-835 humidifier models. Longevity: Reinforced for longer filter life and maximum efficiency. Replacement: It's recommended to replace the filter every two months or seasonally. Maintenance Tip: Turn the filter over each time the humidifier tank is filled to extend its life. Benefits: Contributes to healthier air by removing impurities and preventing the release of contaminants. *PLEASE LOOK AT ALL PICTURES THEY ARE AN IMPORTANT PART OF MY DESCRIPTION! ?? *Shipping: All Orders are Processed Shipped Monday- Friday. Exclude: Holiday of USPS * Any questions: Please send me a message To resolve any issues after purchase: Please Message Me. I am easy to work with and appreciate your business. THANK YOU FOR STOPPING BY; LINDA