HQRP Moisture Wick Filter for Duracraft DH821 DH822 DH822C DH823 DH824 DH799 DH800 DH801 DH812 DH840 DH1005 DH7800 Humidifiers, AC-811 AC-801 D11-C HC-811 Replacement + HQRP Coaster HQRP&reg; Humidifier Wick Filter Replacement + HQRP&reg; Coaster; Removes minerals and pollutants from water; Measures approximately 7 1/4" x 7 3/4" x 1 1/2"; Fits Duracraft & Kenmore humidifiers; Replace your filter every 2 - 3 months (depending on use and local water quality); 2 weeks DOA replacement warranty!