Replacement filter 4. Model K14-3W. Captures dust, pollen, odors and tobacco smoke. Air passing through the humidifier is filtered through the advanced two-stage DynaFilter system. An exclusive cross-woven polyester weave traps pollen, dust and cigarette smoke. A second layer's pulverized coconut-shell activated carbon removes odors and pollutants. The DynaFilter K14 removes 93% of particles as small as pollen from the air. For use with cool mist humidifiers. Made in USA.