Austin Air FR200B Healthmate Junior Replacement Filter, WhiteSTAGE 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). STAGE 3 Over 269 cubic inches of Activated Carbon and Zeolite. Removes chemicals, gases and odors. STAGE 4 30 sq. ft. of True Medical Grade HEPA. Removes 99. 97% of all particles larger than 0. 3 microns and 95% of all particles