These high quality filter wicks are made by a leading manufacturer to fit portable humidifiers from Honeywell, Kaz, Robitussin, and others Patented "Extended Life" design prevents by-pass air, extending the filters higher output Replaces OEM part number HAC-504 and WF2 Replace the filter (evaporating wick) at least once per humidification season or more depending on water conditions in your area Approx dimensions 5" H x 7 OD" x 5" ID x 1" Thick Filter (evaporating wick) should be soaked in water before replacing. DO NOT SQUEEZE OR WRING OUT THE FILTER (Wick). To help extend the life of your filters repeat this step each time you fill your humidifier All product names, logos, brands, trademarks and registered trademarks are property of their respective owners. All company, product and service names used on this page are for identification purposes only. Discount Filters.com and National Trade Supply, LLC are not affiliated with these brands.