These high quality filter wicks are made by a leading manufacturer to fit portable humidifiers from Holmes, Bionaire, Sunbeam, and others. Patented "Extended Life" design prevents by-pass air, extending the filters higher output Anti-bacterial treated Replaces OEM part number HWF-100 Replace the filter (evaporating wick) at least once per humidification season or more depending on water conditions in your area Approx dimensions 5" L x 7-5/8" W x 1" D The wicking filter should be replaced at least one or two times during the season, depending on usage, mineral content of the water and the environment. Completely wet the filters (wicks) with individual frame assemblies in a sink full of coolwater to help reduce mineral build-up. Replace all wetfilters with frame assemblies back into the humidifierbase. 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