Humidifier Wick Filter for Bionaire BWF100 (Aftermarket) by Bionaire Go to amazon.com Related posts Top recommendation for humidifier filter bwf100 FeatureHumidifier Wick Filter for Bionaire BWF100 (Aftermarket)5.25x7.63x1.25 DescriptionPatented Color Check Stripe fades from purple to red as an indiacation of when the filter needs to be changed!