Trion® electronic air cleaners easily attach directly to your home’s heating and cooling system ductwork, passing recirculated air through the air cleaner. A permanent, washable, aluminum mesh pre-filter captures large particles in the air pulled in by the furnace blower. High-voltage ionization within the Trion® exclusive Forever Filter® purifying cell then attracts and captures the particles on alternately charged aluminum plates, filtering up to 95% of particles as minute as 0.1 micron and preventing harmful irritants from being constantly recirculated