The 3-in-1 filter for the Ionmax ION390 UV Air Purifier is a combination of three types of filters in one:
Pre-Filter: Removes larger particles from the air, such as hair, smoke, pollen and dust. Washable.
HEPA Filter: 99.5% HEPA filter filters out particles as small as 0.3 microns from the air.
Deodorising / Carbon Filter: Deodorises and removes odours, smoke and VOCs from the air.