Maintaining healthy indoor air quality and, with this package of three humidifier replacement filters. Are easy to install and have an outer layer for strength. To help you work more efficiently humidifiers, filters for mineral deposits trapped in the water, the more they are treated with Arm & Hammer baking soda and Microban antimicrobial protection for best performance. A new filter humidifier should be installed at the beginning of each season and replaced every two to four weeks depending on usage. The filter works with Bionaire humidifier models BCM4600, BCM645, BCM646, BMC5520, BCM5520RC, BCM5521, BCM4600, BCM5520RCU, BCM6000, BCM6010, BCM6010RC, BCM6610RC, BCM7203, BCM7203RC, BCM7204, BCM7205, BCM7207, BCM7305, BCM7305RCB, BCM-7305RC, BCM7306 and BCM7307. Also fits Holmes models HM729 humidifier, HM729G, HM630, HM7204, HM7305/RC, HM7306, HM6000, HM6000RC, HM6600, HM6005HD and HM4600/HD. The three packages of humidifier filters approximate sizes