Additional carbon filter add-on filtration layer for the pro particle and smoke stop filters. compatible with blueair pro m, pro l and pro xl air purifiers. filter requirements: pro m = 1 filter, pro l = 2 filters, pro xl = 3 filters features a v-shape butterfly fold and contains carbon pellets, designed for maximum removal of airborne pollutants, smoke, vocs, and unwanted odors. to maintain optimal performance, filter change is recommended every 6-12 months (depending on air quality and use).
