Brondell O2+ Filter Replacement Pack Only for Balance P400 and Source P300 Air Purifiers | True HEPA and Carbon Filters Set includes one certified True HEPA and one Granulated Carbon technology replacement filter Filter set is compatible with all Source and Balance O2+ air purification models O2+ replacement filter pack is great for removing allergens like: Dust, Smoke, Pollen, Pet Dander, Odor, Mold, VOCs Easy to replace filter set lasts one (1) year Fits Brondell Balance and Source air purifier models only, not compatible with Halo models