The MicroPower Guard air cleaner uses polarized media technology, which generates an active electromagnetic field to charge both the airborne particles and fibers of the disposable carbon-filled media pad. Polarized particles stick to both the media and to each other. This creates a virtual force field within the ductwork, capturing 97% of the most dangerous-to-breathe sub-micron airborne particles at 0.3 microns. The MicroPower Guard is your first step in improving the indoor air quality of your home and is an essential component of any whole-house air purification system.