This purifier has a built-in Ionizer. Positive ions are converted to negative ions, which promote wellness. The LED feature on the Crystal Aire Purifiers has alternating lights of blue and green which add a tranquil quality to the atmosphere. All the Crystal Aire Purifiers assist in the elimination of bacteria, pet, and tobacco odours and revitalisation of the air. They also prevent mould and fungi growth, removal of pollen and dust from the air, and the reduction of the effects of paint fumes. They work well for adults and children for chest decongestion, they are good for Asthmatics, helping with seasonal allergies, moistening the air and helping with dry coughs. It is ideal for homes, offices, medical rooms, and hotels.