UPGRADE to previously offered Smoke Stop filters, designed for ultimate particle gas and odor removal with no reduction of CADRDUALPROTECTION with activated coconut carbon layer which naturally removes odor causing VOCs and smoke while particle filter captures pollen, dust, pet dander, mold spores, viruses and bacteriaUP TO 4x FASTER pollutant removal than other carbon filtersGENUINE Blue air Replacement Filter is compatible with Blue air Classic 501, Blue air Classic 503, Blue air Classic 510, Blue air Classic 550E, Blue air Classic 555EB, Blue air Classic 580i Blue air Classic 601, Blue air Classic 603, Blue air Classic 650E, Blue air Classic 505, Blue air Classic 605RECOMMENDED to change filter once every 6 months, or dependent on usage. This filter can be recycled after it's changed. The 500/600 Series air purifiers use 3 separate filters, this replacement pack contains a set of 3 filters.