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) STAGE 3 - 15 lbs. of Activated Carbon and Zeolite impregnated with Potassium Iodide • Removes chemicals, gases and odors (e.g. formaldehyde and ammonia) STAGE 4 - 60 ft. of True Medical Grade HEPA • Removes harmful micro-organisms (e.g. bacteria and viruses)