HQRP Filter 6-pack for Bionaire BCM630B BCM630B-CN BCM645 BCM646 BCM646C BCM655 Humidifier + HQRP Coaster HQRP&reg; 6-pack Cool Mist Humidifier Filter Replacement plus HQRP&reg; Coaster; Filter Helps To Capture Mineral Deposits And Improve Efficiency Of The Humidifier; For Maximum Performance Change Filter Every 30 Days; Compatible with Original filter. 2 weeks DOA replacement warranty!