hqrp 4-pack humidifier wick filter compatible with procare pccm-832n pccm-840 cool mist humidifier, ac813 pcwf813 pcwf813-24 replacement hqrp hqrp humidifier filter features honeycomb filtration to trap mineral pollutants found in water and helps prevent them from entering your home. <br>for optimum performance, replace filter at the beginning of each season or every 2 months depending on use. <p>compatible with part # wf813. <br>fits procare pccm-832n, pccm-840 cool mist humidifier, ac813 pcwf813 pcwf813-24 rwf-813 replacement.