HQRP 2pack Humidifier Wick Filter for Duracraft HC832, DH-830 / DH830 Series Cool Moisture Humidifier, AC-813 / AC-813 R / WF-813 Replacement + HQRP Coaster HQRP&reg; 2-pack Wick Humidifier Filter Replacement plus HQRP&reg; Coaster; Removes particles from water; Helps prevent the growth and migration of mold, fungus, algae and bacteria; Replaces Part # WF813; Measures approximately 3.75" x 5.5" x 1.1"; Replace your filter every 1 to 3 months for optimal performance; Compatible with Original filter; 2 weeks DOA replacement warranty!