This is the first stage of filtration for any standard size Austin Air purifier. Its cotton weave traps particles you can see without a microscope, like dust and pet hair. HealthMate HM400 pre filter replacement captures light odors, chemicals and smoke.
Black pre-filters are for the following coloured units: Blue, Black.
White pre-filters are for the following coloured units: Sandstone, White.
Compatible Models: HealthMate, HealthMate Plus, Allergy Machine, Pet Machine and Bedroom Machine.