... efficient,4-Stage air filtration system: Pre-filter + HEPA + Active carbon + N-ion.Eliminate airborne small particles as dust, ... as dust,smoke,ticks and other particulate.It could cut off the transmission of flu virus.Activated carbon filter---Absorbs ... radical,photocatalytic oxidation can effectively disinfect,deodorize and purify air.Smoke and dust sensor---Automatic perceived indoor dust, cigarettes ...