... an Activated Carbon Filter - Absorb mild smoke and odors.6th stage is an Negative Ionizer - Simply to freshen the air comming ... Hospital, Etc..·Filters: Cotton filtering effect early, HEPA Filter, Activated Carbon and Photocatalytic.·UV: 254nm (20,000 Hour Life) Based ... : Depending upon usage, Cotton filtering, HEPA and Carbon: 3 to 6 months, Photocatalytic: 12 months.·MOQ: 500pcs. small air purifier