The Austin Air HealthMate HM400 Filter uses the HEPA to remove up to 99.97 percent of all particles down to 0.3 microns in size and 95 percent down to 0.1 micron.

Filter Specifications 

STAGE 1 – Large Particle Pre-filter. Removes particles easily seen by the naked eye (e.g. dust, hair and pet dander)
STAGE 2 – Medium Particle Pre-filter. Removes small to medium size particles (e.g. molds, spores and pollen) Color: gray, blue or green.
STAGE 3 – Over 780 cubic inches of Activated Carbon and Zeolite.  Removes chemicals, gases and odors.
STAGE 4 – 60 sq. ft. of True Medical Grade HEPA. Removes 99.97% of all particles larger than 0.3 microns and 95% of all particles larger than 0.1 microns.