HQRP 3-Pack Filter for Bionaire Humidifier BCM630, BCM630B, BCM645, BCM646, BCM646C, BCM646BF, BCM600 Coaster HQRP&reg; 3-pack Humidifier Wick Filter (Type E) Replacement + HQRP&reg; Coaster; Improves efficiency of the humidifier; Traps mineral deposits from the water; Treated With an Antimicrobial Agent; Replace filter every 4-6 weeks, depending on usage and hardness of water. 2 weeks DOA replacement warranty!