Duracraft humidifier wick replacement filters. Fits Duracraft Natural Cool MoistureTM Humidifier models DH836, DH837, DH837B, and DH950. Measures approximately 5 1/2" x 6" x 1 1/2". High performance, high output! Honeycomb filtration to trap mineral pollutants found in water and help prevent them from entering your home. For optimum performance, replace filter at the beginning of each season or every 2 months depending on use.